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Sample records for optimize lifecycle maintenance

  1. ITER Remote Maintenance System (IRMS) lifecycle management

    Tesini, Alessandro, E-mail: alessandro.tesini@iter.org [ITER Organization, CS 90 046, 13067 St. Paul Lez Durance Cedex (France); Otto' , Bede [Oxford Technologies Ltd, 7, Nuffield Way, Abingdon, Oxon OX14 1RJ (United Kingdom); Blight, John [FAAST 31c Allee de la Granette, 13600 Ceyreste (France); Choi, Chang-Hwan; Friconneau, Jean-Pierre; Gotewal, Krishan Kumar; Hamilton, David [ITER Organization, CS 90 046, 13067 St. Paul Lez Durance Cedex (France); Heckendorn, Frank [FD Technologies, PO Box 6686, Aiken, SC (United States); Martins, Jean-Pierre [ITER Organization, CS 90 046, 13067 St. Paul Lez Durance Cedex (France); Marty, Thomas [Westinghouse, 122, avenue de Hambourg, 13008 Marseille (France); Nakahira, Masataka; Palmer, Jim; Subramanian, Rajendran [ITER Organization, CS 90 046, 13067 St. Paul Lez Durance Cedex (France)

    2011-10-15

    The availability of the ITER machine to perform its scientific program is strongly dependent on the performance of the different Remote Handling (RH) systems constituting the ITER Remote Maintenance System (IRMS). The lifecycle of the IRMS will largely exceed 40 years from initial concept design and proof testing through to machine decommissioning. Such a long lifecycle requires that a rigorous approach is put in place to guarantee the technical capabilities of the highly innovative IRMS, its efficiency and its availability. For this purpose, an IRMS System Engineering and IRMS lifecycle management approach has been adopted by ITER. The approach aims at ensuring the IRMS full operability and availability at an acceptable cost of ownership over the full ITER machine assembly and operations period. The IRMS lifecycle management method described in this paper covers such subjects as specific requirements for IRMS design reviews, monitoring during manufacture, factory and site acceptance testing, integrated commissioning, decontamination, maintenance and re-qualification strategies, requirements for Integrated Logistical Support during operations. The updating and implementation of the IRMS lifecycle strategy and this procedure will be managed and monitored by the Remote Handling Integrated Product Team (RH-IPT). Although developed for the IRMS, the basic principles and procedures of lifecycle management could be applied to other ITER plant systems whose reliability and availability will be essential for the continued operation of the ITER machine.

  2. ITER Remote Maintenance System (IRMS) lifecycle management

    Tesini, Alessandro; Otto', Bede; Blight, John; Choi, Chang-Hwan; Friconneau, Jean-Pierre; Gotewal, Krishan Kumar; Hamilton, David; Heckendorn, Frank; Martins, Jean-Pierre; Marty, Thomas; Nakahira, Masataka; Palmer, Jim; Subramanian, Rajendran

    2011-01-01

    The availability of the ITER machine to perform its scientific program is strongly dependent on the performance of the different Remote Handling (RH) systems constituting the ITER Remote Maintenance System (IRMS). The lifecycle of the IRMS will largely exceed 40 years from initial concept design and proof testing through to machine decommissioning. Such a long lifecycle requires that a rigorous approach is put in place to guarantee the technical capabilities of the highly innovative IRMS, its efficiency and its availability. For this purpose, an IRMS System Engineering and IRMS lifecycle management approach has been adopted by ITER. The approach aims at ensuring the IRMS full operability and availability at an acceptable cost of ownership over the full ITER machine assembly and operations period. The IRMS lifecycle management method described in this paper covers such subjects as specific requirements for IRMS design reviews, monitoring during manufacture, factory and site acceptance testing, integrated commissioning, decontamination, maintenance and re-qualification strategies, requirements for Integrated Logistical Support during operations. The updating and implementation of the IRMS lifecycle strategy and this procedure will be managed and monitored by the Remote Handling Integrated Product Team (RH-IPT). Although developed for the IRMS, the basic principles and procedures of lifecycle management could be applied to other ITER plant systems whose reliability and availability will be essential for the continued operation of the ITER machine.

  3. Lifecycle-Based Swarm Optimization Method for Numerical Optimization

    Hai Shen

    2014-01-01

    Full Text Available Bioinspired optimization algorithms have been widely used to solve various scientific and engineering problems. Inspired by biological lifecycle, this paper presents a novel optimization algorithm called lifecycle-based swarm optimization (LSO. Biological lifecycle includes four stages: birth, growth, reproduction, and death. With this process, even though individual organism died, the species will not perish. Furthermore, species will have stronger ability of adaptation to the environment and achieve perfect evolution. LSO simulates Biological lifecycle process through six optimization operators: chemotactic, assimilation, transposition, crossover, selection, and mutation. In addition, the spatial distribution of initialization population meets clumped distribution. Experiments were conducted on unconstrained benchmark optimization problems and mechanical design optimization problems. Unconstrained benchmark problems include both unimodal and multimodal cases the demonstration of the optimal performance and stability, and the mechanical design problem was tested for algorithm practicability. The results demonstrate remarkable performance of the LSO algorithm on all chosen benchmark functions when compared to several successful optimization techniques.

  4. Design Buildings Optimally: A Lifecycle Assessment Approach

    Hosny, Ossama

    2013-01-01

    This paper structures a generic framework to support optimum design for multi-buildings in desert environment. The framework is targeting an environmental friendly design with minimum lifecycle cost, using Genetic Algorithms (Gas). GAs function through a set of success measures which evaluates the design, formulates a proper objective, and reflects possible tangible/intangible constraints. The framework optimizes the design and categorizes it under a certain environmental category at minimum Life Cycle Cost (LCC). It consists of three main modules: (1) a custom Building InformationModel (BIM) for desert buildings with a compatibility checker as a central interactive database; (2) a system evaluator module to evaluate the proposed success measures for the design; and (3) a GAs optimization module to ensure optimum design. The framework functions through three levels: the building components, integrated building, and multi-building levels. At the component level the design team should be able to select components in a designed sequence to ensure compatibility among various components, while at the building level; the team can relatively locate and orient each individual building. Finally, at the multi-building (compound) level the whole design can be evaluated using success measures of natural light, site capacity, shading impact on natural lighting, thermal change, visual access and energy saving. The framework through genetic algorithms optimizes the design by determining proper types of building components and relative buildings locations and orientations which ensure categorizing the design under a specific category or meet certain preferences at minimum lifecycle cost.

  5. Optimization of surface maintenance

    Oeverland, E.

    1990-01-01

    The present conference paper deals with methods of optimizing the surface maintenance of steel-made offshore installations. The paper aims at identifying important approaches to the problems regarding the long-range planning of an economical and cost effective maintenance program. The methods of optimization are based on the obtained experiences from the maintenance of installations on the Norwegian continental shelf. 3 figs

  6. Maintenance optimization after RCM

    Doyle, E.K.; Lee, C.-G.; Cho, D.

    2005-01-01

    Variant forms of RCM (Reliability Centered Maintenance) have been the maintenance optimizing tools of choice in industry for the last 20 years. Several such optimization techniques have been implemented at the Bruce Nuclear Station. Further cost refinement of the Station preventive maintenance strategy whereby decisions are based on statistical analysis of historical failure data are now being evaluated. The evaluation includes a requirement to demonstrate that earlier optimization projects have long term positive impacts. This proved to be a significant challenge. Eventually a methodology was developed using Crowe/AMSAA (Army Materials Systems Analysis Activity) plots to justify expenditures on further optimization efforts. (authors)

  7. Initiating statistical maintenance optimization

    Doyle, E. Kevin; Tuomi, Vesa; Rowley, Ian

    2007-01-01

    Since the 1980 s maintenance optimization has been centered around various formulations of Reliability Centered Maintenance (RCM). Several such optimization techniques have been implemented at the Bruce Nuclear Station. Further cost refinement of the Station preventive maintenance strategy includes evaluation of statistical optimization techniques. A review of successful pilot efforts in this direction is provided as well as initial work with graphical analysis. The present situation reguarding data sourcing, the principle impediment to use of stochastic methods in previous years, is discussed. The use of Crowe/AMSAA (Army Materials Systems Analysis Activity) plots is demonstrated from the point of view of justifying expenditures in optimization efforts. (author)

  8. Lifecycle optimized ethanol-gasoline blends for turbocharged engines

    Zhang, Bo; Sarathy, Mani

    2016-01-01

    This study presents a lifecycle (well-to-wheel) analysis to determine the CO2 emissions associated with ethanol blended gasoline in optimized turbocharged engines. This study provides a more accurate assessment on the best-achievable CO2 emission

  9. Optimizing preventive maintenance with maintenance templates

    Dozier, I.J.

    1996-01-01

    Rising operating costs has caused maintenance professionals to rethink their strategy for preventive maintenance (PM) programs. Maintenance Templates are pre-engineered PM task recommendations for a component type based on application of the component. Development of the maintenance template considers the dominant failure cause of the component and the type of preventive maintenance that can predict or prevent the failure from occurring. Maintenance template development also attempts to replace fixed frequency tasks with condition monitoring tasks such as vibration analysis or thermography. For those components that have fixed frequency PM intervals, consideration is given to the maintenance drivers such as criticality, environment and usage. This helps to maximize the PM frequency intervals and maximize the component availability. Maintenance Templates have been used at PECO Energy's Limerick Generating Station during the Reliability Centered Maintenance (RCM) Process to optimize their PM program. This paper describes the development and uses of the maintenance templates

  10. Lifecycle optimized ethanol-gasoline blends for turbocharged engines

    Zhang, Bo

    2016-08-16

    This study presents a lifecycle (well-to-wheel) analysis to determine the CO2 emissions associated with ethanol blended gasoline in optimized turbocharged engines. This study provides a more accurate assessment on the best-achievable CO2 emission of ethanol blended gasoline mixtures in future engines. The optimal fuel blend (lowest CO2 emitting fuel) is identified. A range of gasoline fuels is studied, containing different ethanol volume percentages (E0–E40), research octane numbers (RON, 92–105), and octane sensitivities (8.5–15.5). Sugarcane-based and cellulosic ethanol-blended gasolines are shown to be effective in reducing lifecycle CO2 emission, while corn-based ethanol is not as effective. A refinery simulation of production emission was utilized, and combined with vehicle fuel consumption modeling to determine the lifecycle CO2 emissions associated with ethanol-blended gasoline in turbocharged engines. The critical parameters studied, and related to blended fuel lifecycle CO2 emissions, are ethanol content, research octane number, and octane sensitivity. The lowest-emitting blended fuel had an ethanol content of 32 vol%, RON of 105, and octane sensitivity of 15.5; resulting in a CO2 reduction of 7.1%, compared to the reference gasoline fuel and engine technology. The advantage of ethanol addition is greatest on a per unit basis at low concentrations. Finally, this study shows that engine-downsizing technology can yield an additional CO2 reduction of up to 25.5% in a two-stage downsized turbocharged engine burning the optimum sugarcane-based fuel blend. The social cost savings in the USA, from the CO2 reduction, is estimated to be as much as $187 billion/year. © 2016 Elsevier Ltd

  11. Optimizing preventive maintenance

    DiCola, F.E.

    1988-01-01

    The traditional approach to preventive maintenance (PM) is based on adherence to manufacturers's requirements and recommended frequencies. When equipment fails, either new procedures are established or the frequency is increased. This leads to an increase in the number of PM activities, overloading not only maintenance resources, but support as well. There is no correlation between more PM and an increase in equipment reliability. More PM may actually induce failures. Reliability-centered maintenance, a new concept in utility maintenance, is based on identifying system/subsystem functions, failures, and dominant failure modes to develop or revise PM tasks. The activities described in this paper are based on actual implementation of this concept on an ongoing project to upgrade the PM program at one of the largest electric utilities in the country. Optimum PM activities are those that, when implemented, will minimize factors that c cause equipment to fail. One technique described illustrates how equipment performance, failure modes, and causes can be related to minimize the occurrence of failures. Operating history and service life of a component are key factors in determining the most effective PM activities, provided that the factors are related to failure modes and causes

  12. Developing optimized prioritizing road maintenance

    Ewadh Hussein Ali

    2018-01-01

    Full Text Available Increased demand for efficient maintenance of the existing roadway system needs optimal usage of the allocated funds. The paper demonstrates optimized methods for prioritizing maintenance implementation projects. A selected zone of roadway system in Kerbala city represents the study area to demonstrate the application of the developed prioritization process. Paver system PAVER integrated with GIS is used to estimate and display the pavement condition index PCI, thereby to establish a priority of maintenance. In addition to simple ranking method by PCI produced by the output of PAVER, the paper introduces PCI measure for each section of roadway. The paper introduces ranking by multiple measures investigated through expert knowledge about measures that affect prioritization and their irrespective weights due to a predesigned questionnaire. The maintenance priority index (MPI is related to cost of suitable proposed maintenance, easiness of proposed maintenance, average daily traffic and functional classification of the roadway in addition to PCI. Further, incremental benefit-cost analysis ranking provide an optimized process due to benefit and cost of maintenance. The paper introduces efficient display of layout and ranking for the selected zone of roadway system based on MPI index and incremental BCR method. Although the two developed methods introduce different layout display for priority, statistical test shows that no significant difference between ranking of all methods of prioritization.

  13. A two-level strategy to realize life-cycle production optimization in an operational setting

    Essen, van G.M.; Hof, Van den P.M.J.; Jansen, J.D.

    2012-01-01

    We present a two-level strategy to improve robustness against uncertainty and model errors in life-cycle flooding optimization. At the upper level, a physics-based large-scale reservoir model is used to determine optimal life-cycle injection and production profiles. At the lower level these profiles

  14. A two-level strategy to realize life-cycle production optimization in an operational setting

    Essen, van G.M.; Hof, Van den P.M.J.; Jansen, J.D.

    2013-01-01

    We present a two-level strategy to improve robustness against uncertainty and model errors in life-cycle flooding optimization. At the upper level, a physics-based large-scale reservoir model is used to determine optimal life-cycle injection and production profiles. At the lower level these profiles

  15. Optimal Life-Cycle Investing with Flexible Labor Supply: A Welfare Analysis of Life-Cycle Funds

    Francisco J. Gomes; Laurence J. Kotlikoff; Luis M. Viceira

    2008-01-01

    We investigate optimal consumption, asset accumulation and portfolio decisions in a realistically calibrated life-cycle model with flexible labor supply. Our framework allows for wage rate uncertainly, variable labor supply, social security benefits and portfolio choice over safe bonds and risky equities. Our analysis reinforces prior findings that equities are the preferred asset for young households, with the optimal share of equities generally declining prior to retirement. However, variab...

  16. Optimal, Risk-based Operation and Maintenance Planning for Offshore Wind Turbines

    Sørensen, John Dalsgaard

    2008-01-01

    For offshore wind turbines costs to operation and maintenance are substantial. This paper describes a risk-based life-cycle approach for optimal planning of operation and maintenance. The approach is based on pre-posterior Bayesian decision theory. Deterioration mechanisms such as fatigue...

  17. Optimal life-cycle profiles of fertility and labor supply.

    Moffitt, R

    1984-01-01

    A model of life cycle fertility is developed using the language and framework of optimal control theory. The chief characteristic of children that distinguishes them from other consumer durables is, in the language of the optimal growth theory, the "irreversibility of investment." As the good does not depreciate in the ordinary sense, the stock must be monotonically nondecreasing over time. The optimal profile of fertility is, for this reason, characterized by the same type of "bang-bang" behavior found in many optimal growth problems. Yet, the fertility decision is complicated considerably by several other factors. Chief among these is the intrinsic relation to the labor-supply decision, for having children implies inevitable constraints on the mother's or father's time. Thus, optimal labor-supply decisions also must be considered. The model is developed in stages, proceeding from very simple to the more complex models. 1 section introduces the impact of fertility on the future demands for home time. It is shown that optimal fertility profiles follow turnpike paths similar to those in the growth-theory literature. A subsequent section introduces labor-supply and human-captial considerations. As the models become more complex, solutions become harder to derive and are often only outlined. The analysis provides some theoretical basis for expecting certain shapes of the life-cycle profiles of fertility, labor supply, and wages. Fertility profiles may be of 2 shapes--one beginning at a high rate, falling to a lower rate, then to zero; and one beginning at zero, rising to a moderate rate, then falling back down to zero. Labor supply profiles can be of a number of different shapes, but the impact of childbearing is to lower hours worked during the early childrearing period. As the children mature, hours worked rise (or at least fall more slowly) as home time responsibilities lessen, although the level to which they rise will probably be lower than before the 1st birth

  18. Integrated Life-Cycle Framework for Maintenance, Monitoring and Reliability of Naval Ship Structures

    2012-08-15

    uncertainty in quantitative risk and policy analysis, Cambridge Univer- sity Press. NEVES, L. C, FRANGOPOL, D. M., AND CRUZ , P. J. 2006 Probabilistic lifetime...L. C, FRANGOPOL, D. M., AND CRUZ , P. J. 2006 Probabilistic life- time-oriented multiobjective optimization of bridge maintenance: single...Wright Aeronautical Laboratory. Wright- Patterson Air Force Base, Dayton, Ohio; 1981. [5| Chung H-Y, Manuel L, Frank KH. Optimal inspection

  19. An ensemble-based method for constrained reservoir life-cycle optimization

    Leeuwenburgh, O.; Egberts, P.J.P.; Chitu, A.G.

    2015-01-01

    We consider the problem of finding optimal long-term (life-cycle) recovery strategies for hydrocarbon reservoirs by use of simulation models. In such problems the presence of operating constraints, such as for example a maximum rate limit for a group of wells, may strongly influence the range of

  20. Maintenance Optimization of High Voltage Substation Model

    Radim Bris

    2008-01-01

    Full Text Available The real system from practice is selected for optimization purpose in this paper. We describe the real scheme of a high voltage (HV substation in different work states. Model scheme of the HV substation 22 kV is demonstrated within the paper. The scheme serves as input model scheme for the maintenance optimization. The input reliability and cost parameters of all components are given: the preventive and corrective maintenance costs, the actual maintenance period (being optimized, the failure rate and mean time to repair - MTTR.

  1. Optimal maintenance of a multi-unit system under dependencies

    Sung, Ho-Joon

    The availability, or reliability, of an engineering component greatly influences the operational cost and safety characteristics of a modern system over its life-cycle. Until recently, the reliance on past empirical data has been the industry-standard practice to develop maintenance policies that provide the minimum level of system reliability. Because such empirically-derived policies are vulnerable to unforeseen or fast-changing external factors, recent advancements in the study of topic on maintenance, which is known as optimal maintenance problem, has gained considerable interest as a legitimate area of research. An extensive body of applicable work is available, ranging from those concerned with identifying maintenance policies aimed at providing required system availability at minimum possible cost, to topics on imperfect maintenance of multi-unit system under dependencies. Nonetheless, these existing mathematical approaches to solve for optimal maintenance policies must be treated with caution when considered for broader applications, as they are accompanied by specialized treatments to ease the mathematical derivation of unknown functions in both objective function and constraint for a given optimal maintenance problem. These unknown functions are defined as reliability measures in this thesis, and theses measures (e.g., expected number of failures, system renewal cycle, expected system up time, etc.) do not often lend themselves to possess closed-form formulas. It is thus quite common to impose simplifying assumptions on input probability distributions of components' lifetime or repair policies. Simplifying the complex structure of a multi-unit system to a k-out-of-n system by neglecting any sources of dependencies is another commonly practiced technique intended to increase the mathematical tractability of a particular model. This dissertation presents a proposal for an alternative methodology to solve optimal maintenance problems by aiming to achieve the

  2. Life-cycle cost assessment of optimally designed reinforced concrete buildings under seismic actions

    Mitropoulou, Chara Ch.; Lagaros, Nikos D.; Papadrakakis, Manolis

    2011-01-01

    Life-cycle cost analysis (LCCA) is an assessment tool for studying the performance of systems in many fields of engineering. In earthquake engineering LCCA demands the calculation of the cost components that are related to the performance of the structure in multiple earthquake hazard levels. Incremental static and dynamic analyses are two procedures that can be used for estimating the seismic capacity of a structural system and can therefore be incorporated into the LCCA methodology. In this work the effect of the analysis procedure, the number of seismic records imposed, the performance criterion used and the structural type (regular or irregular) is investigated, on the life-cycle cost analysis of 3D reinforced concrete structures. Furthermore, the influence of uncertainties on the seismic response of structural systems and their impact on LCCA is examined. The uncertainty on the material properties, the cross-section dimensions and the record-incident angle is taking into account with the incorporation of the Latin hypercube sampling method into the incremental dynamic analysis procedure. In addition, the LCCA methodology is used as an assessment tool for the designs obtained by means of prescriptive and performance-based optimum design methodologies. The first one is obtained from a single-objective optimization problem, where the initial construction cost was the objective to be minimized, while the second one as a two-objective optimization problem where the life-cycle cost was the additional objective also to be minimized.

  3. Performance deterioration modeling and optimal preventive maintenance strategy under scheduled servicing subject to mission time

    Li Dawei

    2014-08-01

    Full Text Available Servicing is applied periodically in practice with the aim of restoring the system state and prolonging the lifetime. It is generally seen as an imperfect maintenance action which has a chief influence on the maintenance strategy. In order to model the maintenance effect of servicing, this study analyzes the deterioration characteristics of system under scheduled servicing. And then the deterioration model is established from the failure mechanism by compound Poisson process. On the basis of the system damage value and failure mechanism, the failure rate refresh factor is proposed to describe the maintenance effect of servicing. A maintenance strategy is developed which combines the benefits of scheduled servicing and preventive maintenance. Then the optimization model is given to determine the optimal servicing period and preventive maintenance time, with an objective to minimize the system expected life-cycle cost per unit time and a constraint on system survival probability for the duration of mission time. Subject to mission time, it can control the ability of accomplishing the mission at any time so as to ensure the high dependability. An example of water pump rotor relating to scheduled servicing is introduced to illustrate the failure rate refresh factor and the proposed maintenance strategy. Compared with traditional methods, the numerical results show that the failure rate refresh factor can describe the maintenance effect of servicing more intuitively and objectively. It also demonstrates that this maintenance strategy can prolong the lifetime, reduce the total lifetime maintenance cost and guarantee the dependability of system.

  4. Maintenance optimization plan for essential equipment reliability

    Steffen, D.H.

    1996-02-01

    The Maintenance Optimization Plan (MOP) for Essential Equipment Reliability will furnish Tank Waste Remediation System (TWRS) management with a pro-active, forward-thinking process for maintaining essential structures, systems, and components (ESSC) at the Hanford Site tank farms in their designed condition, and to ensure optimum ESSC availability and reliability

  5. Probabilistic methods for maintenance program optimization

    Liming, J.K.; Smith, M.J.; Gekler, W.C.

    1989-01-01

    In today's regulatory and economic environments, it is more important than ever that managers, engineers, and plant staff join together in developing and implementing effective management plans for safety and economic risk. This need applied to both power generating stations and other process facilities. One of the most critical parts of these management plans is the development and continuous enhancement of a maintenance program that optimizes plant or facility safety and profitability. The ultimate objective is to maximize the potential for station or facility success, usually measured in terms of projected financial profitability, while meeting or exceeding meaningful and reasonable safety goals, usually measured in terms of projected damage or consequence frequencies. This paper describes the use of the latest concepts in developing and evaluating maintenance programs to achieve maintenance program optimization (MPO). These concepts are based on significant field experience gained through the integration and application of fundamentals developed for industry and Electric Power Research Institute (EPRI)-sponsored projects on preventive maintenance (PM) program development and reliability-centered maintenance (RCM)

  6. Stochastic maintenance optimization at Candu power plants

    Doyle, E.K.; Duchesne, T.; Lee, C.G.; Cho, D.I.

    2004-01-01

    The use of various innovative maintenance optimization techniques at Bruce has lead to cost effective preventive maintenance applications for complex systems as previously reported at ICONE 6 in New Orleans (1996). Further refinement of the station maintenance strategy was evaluated via the applicability of statistical analysis of historical failure data. The viability of stochastic methods in Candu maintenance was illustrated at ICONE 10 in Washington DC (2002). The next phase consists of investigating the validity of using subjective elicitation techniques to obtain component lifetime distributions. This technique provides access to the elusive failure statistics, the lack of which is often referred to in the literature as the principal impediment preventing the use of stochastic methods in large industry. At the same time the technique allows very valuable information to be captured from the fast retiring 'baby boom generation'. Initial indications have been quite positive. The current reality of global competition necessitates the pursuit of all financial optimizers. The next construction phase in the power generation industry will soon begin on a worldwide basis. With the relatively high initial capital cost of new nuclear generation all possible avenues of financial optimization must be evaluated and implemented. (authors)

  7. Road maintenance optimization through a discrete-time semi-Markov decision process

    Zhang Xueqing; Gao Hui

    2012-01-01

    Optimization models are necessary for efficient and cost-effective maintenance of a road network. In this regard, road deterioration is commonly modeled as a discrete-time Markov process such that an optimal maintenance policy can be obtained based on the Markov decision process, or as a renewal process such that an optimal maintenance policy can be obtained based on the renewal theory. However, the discrete-time Markov process cannot capture the real time at which the state transits while the renewal process considers only one state and one maintenance action. In this paper, road deterioration is modeled as a semi-Markov process in which the state transition has the Markov property and the holding time in each state is assumed to follow a discrete Weibull distribution. Based on this semi-Markov process, linear programming models are formulated for both infinite and finite planning horizons in order to derive optimal maintenance policies to minimize the life-cycle cost of a road network. A hypothetical road network is used to illustrate the application of the proposed optimization models. The results indicate that these linear programming models are practical for the maintenance of a road network having a large number of road segments and that they are convenient to incorporate various constraints on the decision process, for example, performance requirements and available budgets. Although the optimal maintenance policies obtained for the road network are randomized stationary policies, the extent of this randomness in decision making is limited. The maintenance actions are deterministic for most states and the randomness in selecting actions occurs only for a few states.

  8. Evaluation of Externality Costs in Life-Cycle Optimization of Municipal Solid Waste Management Systems

    Martinez Sanchez, Veronica; Levis, James W.; Damgaard, Anders

    2017-01-01

    The development of sustainable solid waste management (SWM) systems requires consideration of both economic and environmental impacts. Societal life-cycle costing (S-LCC) provides a quantitative framework to estimate both economic and environmental impacts, by including "budget costs...... suburban U.S. county of 500 000 people generating 320 000 Mg of waste annually. Estimated externality costs are based on emissions of CO2, CH4, N2O, PM2.5, PM10, NOx, SO2, VOC, CO, NH3, Hg, Pb, Cd, Cr (VI), Ni, As, and dioxins. The results indicate that incorporating S-LCC into optimized SWM strategy...... development encourages the use of a mixed waste material recovery facility with residues going to incineration, and separated organics to anaerobic digestion. Results are sensitive to waste composition, energy mix and recycling rates. Most of the externality costs stem from SO2, NOx, PM2.5, CH4, fossil CO2...

  9. Maintenance optimization for subsea oil pipelines

    Castanier, Bruno; Rausand, Marvin

    2006-01-01

    In this paper, the classical PF interval model, proposed for reliability centered maintenance, is used to optimize the preventive replacement policy of a subsea oil pipeline. The pipeline is subject to failure modes that may lead to oil release and pollution of the sea. The proposed replacement policy is based on regular condition measurements of the quality of an internal pipeline coating (lining). Holes in the coating will expose the pipe material (steel) to a corrosive environment. It is, therefore, important to identify holes in the coating and take action before the corrosion penetrates the pipe wall. The model proposed in the paper can be used to determine the inspection interval that minimizes the average maintenance cost per time unit. The model formulation is outlined and illustrative examples are solved. The mathematical evaluation of the replacement policy requires numerous assumptions. These assumptions have to be tailored to the specific application. The assumptions and the data provided are included for illustrative purposes to exemplify potential results that may be obtained by using the replacement policy

  10. Using heuristic search for optimizing maintenance plans

    Mutanen, Teemu

    2012-01-01

    This work addresses the maintenance action selection process. Maintenance personnel need to evaluate maintenance actions and costs to keep the machines in working condition. Group of actions are evaluated together as maintenance plans. The maintenance plans as output provide information to the user about which actions to take if any and what future actions should be prepared for. The heuristic search method is implemented as part of general use toolbox for analysis of measurements from movable work machines. Impacts from machine's usage restrictions and maintenance activities are analysed. The results show that once put on a temporal perspective, the prioritized order of the actions is different and provide additional information to the user.

  11. LIFE-CYCLE COST MODEL AND DESIGN OPTIMIZATION OF BASE ISOLATED BUILDING STRUCTURES

    Chara C. Mitropoulou

    2016-11-01

    Full Text Available Design of economic structures adequately resistant to withstand during their service life, without catastrophic failures, all possible loading conditions and to absorb the induced seismic energy in a controlled fashion, has been the subject of intensive research so far. Modern buildings usually contain extremely sensitive and costly equipment that are vital in business, commerce, education and/or health care. The building contents frequently are more valuable than the buildings them-selves. Furthermore, hospitals, communication and emergency centres, police and fire stations must be operational when needed most: immediately after an earthquake. Conventional con-struction can cause very high floor accelerations in stiff buildings and large interstorey drifts in flexible structures. These two factors cause difficulties in insuring the safety of both building and its contents. For this reason base-isolated structures are considered as an efficient alternative design practice to the conventional fixed-base one. In this study a systematic assessment of op-timized fixed and base-isolated reinforced concrete buildings is presented in terms of their initial and total cost taking into account the life-cycle cost of the structures.

  12. An Adaptive Bacterial Foraging Optimization Algorithm with Lifecycle and Social Learning

    Xiaohui Yan

    2012-01-01

    Full Text Available Bacterial Foraging Algorithm (BFO is a recently proposed swarm intelligence algorithm inspired by the foraging and chemotactic phenomenon of bacteria. However, its optimization ability is not so good compared with other classic algorithms as it has several shortages. This paper presents an improved BFO Algorithm. In the new algorithm, a lifecycle model of bacteria is founded. The bacteria could split, die, or migrate dynamically in the foraging processes, and population size varies as the algorithm runs. Social learning is also introduced so that the bacteria will tumble towards better directions in the chemotactic steps. Besides, adaptive step lengths are employed in chemotaxis. The new algorithm is named BFOLS and it is tested on a set of benchmark functions with dimensions of 2 and 20. Canonical BFO, PSO, and GA algorithms are employed for comparison. Experiment results and statistic analysis show that the BFOLS algorithm offers significant improvements than original BFO algorithm. Particulary with dimension of 20, it has the best performance among the four algorithms.

  13. Optimizing block-based maintenance under random machine usage

    de Jonge, Bram; Jakobsons, Edgars

    Existing studies on maintenance optimization generally assume that machines are either used continuously, or that times until failure do not depend on the actual usage. In practice, however, these assumptions are often not realistic. In this paper, we consider block-based maintenance optimization

  14. Optimization of radiation protection of cell maintenance of radiopharmaceutical production

    Machado, Jessica S.; Gerulis, Eduardo; Todo, Alberto S.; Rodrigues Junior, Orlando

    2011-01-01

    This paper performs a study of maintenance tasks realized in production cells to suggest improvements related to the occupational doses based on the optimization principle of the radioprotection. A data survey has been realized of the doses received by the workers during the maintenance. The average values of effective doses are lower than the limits established in the regulations, however can be optimized

  15. Hybrid Optimization Algorithm of Particle Swarm Optimization and Cuckoo Search for Preventive Maintenance Period Optimization

    Jianwen Guo

    2016-01-01

    Full Text Available All equipment must be maintained during its lifetime to ensure normal operation. Maintenance is one of the critical roles in the success of manufacturing enterprises. This paper proposed a preventive maintenance period optimization model (PMPOM to find an optimal preventive maintenance period. By making use of the advantages of particle swarm optimization (PSO and cuckoo search (CS algorithm, a hybrid optimization algorithm of PSO and CS is proposed to solve the PMPOM problem. The test functions show that the proposed algorithm exhibits more outstanding performance than particle swarm optimization and cuckoo search. Experiment results show that the proposed algorithm has advantages of strong optimization ability and fast convergence speed to solve the PMPOM problem.

  16. PSO Based Optimization of Testing and Maintenance Cost in NPPs

    Qiang Chou

    2014-01-01

    Full Text Available Testing and maintenance activities of safety equipment have drawn much attention in Nuclear Power Plant (NPP to risk and cost control. The testing and maintenance activities are often implemented in compliance with the technical specification and maintenance requirements. Technical specification and maintenance-related parameters, that is, allowed outage time (AOT, maintenance period and duration, and so forth, in NPP are associated with controlling risk level and operating cost which need to be minimized. The above problems can be formulated by a constrained multiobjective optimization model, which is widely used in many other engineering problems. Particle swarm optimizations (PSOs have proved their capability to solve these kinds of problems. In this paper, we adopt PSO as an optimizer to optimize the multiobjective optimization problem by iteratively trying to improve a candidate solution with regard to a given measure of quality. Numerical results have demonstrated the efficiency of our proposed algorithm.

  17. On-orbit servicing system assessment and optimization methods based on lifecycle simulation under mixed aleatory and epistemic uncertainties

    Yao, Wen; Chen, Xiaoqian; Huang, Yiyong; van Tooren, Michel

    2013-06-01

    To assess the on-orbit servicing (OOS) paradigm and optimize its utilities by taking advantage of its inherent flexibility and responsiveness, the OOS system assessment and optimization methods based on lifecycle simulation under uncertainties are studied. The uncertainty sources considered in this paper include both the aleatory (random launch/OOS operation failure and on-orbit component failure) and the epistemic (the unknown trend of the end-used market price) types. Firstly, the lifecycle simulation under uncertainties is discussed. The chronological flowchart is presented. The cost and benefit models are established, and the uncertainties thereof are modeled. The dynamic programming method to make optimal decision in face of the uncertain events is introduced. Secondly, the method to analyze the propagation effects of the uncertainties on the OOS utilities is studied. With combined probability and evidence theory, a Monte Carlo lifecycle Simulation based Unified Uncertainty Analysis (MCS-UUA) approach is proposed, based on which the OOS utility assessment tool under mixed uncertainties is developed. Thirdly, to further optimize the OOS system under mixed uncertainties, the reliability-based optimization (RBO) method is studied. To alleviate the computational burden of the traditional RBO method which involves nested optimum search and uncertainty analysis, the framework of Sequential Optimization and Mixed Uncertainty Analysis (SOMUA) is employed to integrate MCS-UUA, and the RBO algorithm SOMUA-MCS is developed. Fourthly, a case study on the OOS system for a hypothetical GEO commercial communication satellite is investigated with the proposed assessment tool. Furthermore, the OOS system is optimized with SOMUA-MCS. Lastly, some conclusions are given and future research prospects are highlighted.

  18. Jointly Production and Correlated Maintenance Optimization for Parallel Leased Machines

    Tarek ASKRI

    2017-04-01

    Full Text Available This paper deals with a preventive maintenance strategy optimization correlated to production for a manufacturing system made by several parallel machines under lease contract. In order to minimize the total cost of production and maintenance by reducing the production system interruptions due to maintenance activities, a correlated group preventive maintenance policy is developed using the gravity center approach (GCA. The aim of this study is to determine an economical production plan and an optimal group preventive maintenance interval Tn at which all machines are maintained simultaneously. An analytical correlation between failure rate of machines and production level is considered and the impact of the preventive maintenance policy on the production plan is studied. Finally, the proposed maintenance policy GPM is compared with an individual simple strategy approach IPM in order to illustrate its efficiency.

  19. Discounted cost model for condition-based maintenance optimization

    Weide, J.A.M. van der; Pandey, M.D.; Noortwijk, J.M. van

    2010-01-01

    This paper presents methods to evaluate the reliability and optimize the maintenance of engineering systems that are damaged by shocks or transients arriving randomly in time and overall degradation is modeled as a cumulative stochastic point process. The paper presents a conceptually clear and comprehensive derivation of formulas for computing the discounted cost associated with a maintenance policy combining both condition-based and age-based criteria for preventive maintenance. The proposed discounted cost model provides a more realistic basis for optimizing the maintenance policies than those based on the asymptotic, non-discounted cost rate criterion.

  20. Joint optimization of production scheduling and machine group preventive maintenance

    Xiao, Lei; Song, Sanling; Chen, Xiaohui; Coit, David W.

    2016-01-01

    Joint optimization models were developed combining group preventive maintenance of a series system and production scheduling. In this paper, we propose a joint optimization model to minimize the total cost including production cost, preventive maintenance cost, minimal repair cost for unexpected failures and tardiness cost. The total cost depends on both the production process and the machine maintenance plan associated with reliability. For the problems addressed in this research, any machine unavailability leads to system downtime. Therefore, it is important to optimize the preventive maintenance of machines because their performance impacts the collective production processing associated with all machines. Too lengthy preventive maintenance intervals may be associated with low scheduled machine maintenance cost, but may incur expensive costs for unplanned failure due to low machine reliability. Alternatively, too frequent preventive maintenance activities may achieve the desired high reliability machines, but unacceptably high scheduled maintenance cost. Additionally, product scheduling plans affect tardiness and maintenance cost. Two results are obtained when solving the problem; the optimal group preventive maintenance interval for machines, and the assignment of each job, including the corresponding start time and completion time. To solve this non-deterministic polynomial-time problem, random keys genetic algorithms are used, and a numerical example is solved to illustrate the proposed model. - Highlights: • Group preventive maintenance (PM) planning and production scheduling are jointed. • Maintenance interval and assignment of jobs are decided by minimizing total cost. • Relationships among system age, PM, job processing time are quantified. • Random keys genetic algorithms (GA) are used to solve the NP-hard problem. • Random keys GA and Particle Swarm Optimization (PSO) are compared.

  1. Maintenance resources optimization applied to a manufacturing system

    Fiori de Castro, Helio; Lucchesi Cavalca, Katia

    2006-01-01

    This paper presents an availability optimization of an engineering system assembled in a series configuration, with redundancy of units and corrective maintenance resources as optimization parameters. The aim is to reach maximum availability, considering as constraints installation and corrective maintenance costs, weight and volume. The optimization method uses a Genetic Algorithm based on biological concepts of species evolution. It is a robust method, as it does not converge to a local optimum. It does not require the use of differential calculus, thus facilitating computational implementation. Results indicate that the methodology is suitable to solve a wide range of engineering design problems involving allocation of redundancies and maintenance resources

  2. Dr. Mainte. Integrated simulator of maintenance optimization of LWRs

    Isobe, Yoshihiro; Sagisaka, Mitsuyuki; Etoh, Junji; Matsunaga, Takashi; Kosaka, Toru; Matsumoto, Satoshi; Yoshimura, Shinobu

    2014-01-01

    Dr. Mainte, an integrated simulator for maintenance optimization of LWRs (Light Water Reactors) has been developed based on PFM (Probabilistic Fracture Mechanics) analyses. The concept of the simulator is to provide a decision-making system to optimize maintenance activities for representative components and piping systems in nuclear power plants totally and quantitatively in terms of safety, availability and economic efficiency, environmental impact and social acceptance. For the further improvement of the safety and availability, the effect of human error and its reduction on the optimization of plant maintenance activities and approaches of reducing it have been studied. (author)

  3. Lifecycle performance. Special issue on management and maintenance, hybrid ventilation concepts, installation-low buildings; Lifecycle performance. Themanummer over beheer en onderhoud, hybride ventilatieconcepten, installatie-arme gebouwen

    Thierauf, I. [Universiteit Utrecht, Utrecht (Netherlands); Kurvers, S.R.; Van den Ham, E.R.; Leijten, J.L. [Sectie Climate Design and Sustainability, Afdeling Architectural Engineering and Technology, Faculteit Bouwkunde, Technische Universiteit Delft TUD, Delft (Netherlands); Juricic, S. [Ecole National des Travaux Publics de l' Etat, Lyon (France); Jacobs, P. [Afdeling Energy and Comfort Systems, TNO, Delft (Netherlands); Versteeg, H. [LBP Sight, Nieuwegein (Netherlands); Van Loon, P.P.M. [Stichting Scholen van Morgen, Rotterdam (Netherlands); Hoek, H.C.; Van Eeden, H.; Nibbelink, J. [Collectief C-on, Haarlem (Netherlands); Veerman, J.; Maassen, W.H. [Royal Haskoning DHV, Nijmegen (Netherlands); Derksen, A.H.P. [ISSO, Rotterdam (Netherlands); Morren, K. [Universiteit Twente, Enschede (Netherlands)

    2012-12-15

    In 9 articles various aspects regarding the title topic are discussed: energy efficiency and user comfort, ventilation in new houses with balanced ventilation, the revised assessment for ventilation performance, air quality in school buildings, buildings with only a few installations, hybrid ventilation, the management and maintenance process, and future performance requirements [Dutch] In 9 artikelen wordt aandacht besteed aan diverse aspecten m.b.t. het titelonderwerp: energie-efficientie en gebruikerscomfort, ventilatie in nieuwbouwwoningen met balansventilatie, de herziene beoordelingsrichtlijn ventilatie prestatie, luchtkwaliteit in schoolgebouwen, installatie-arme gebouwen, hybride ventilatie, het beheer- en onderhoudsproces, en de toekomstige prestatie-eisen.

  4. Optimal maintenance work organization and technical education

    Toshiro Kitamura

    2005-01-01

    Under Japanese multi-layered maintenance routines, almost 100% of work is delegated to outside contractors. For taking such form, there are several reasons unique to Japan. U.S. maintenance work organization makes a contrast, reducing the volume of subcontract in these past ten years. On the other hand, France has a trend of increasing the volume of subcontract for cost reduction that is expected in liberalization and privatization. In Japan, since the subcontract went too far, there is a trend that the multi-layered subcontract structure will be relieved. The Japan Atomic Power, Inc., has organized a team that performs a part of maintenance work by employees themselves since three years before. Direct work is effective to greatly supporting the employees' technical ability. It is expected that the quality of subcontract management will be markedly improved from now on. (author)

  5. Optimal maintenance of multi-component systems: a review

    R.P. Nicolai (Robin); R. Dekker (Rommert)

    2006-01-01

    textabstractIn this article we give an overview of the literature on multi-component maintenance optimization. We focus on work appearing since the 1991 survey "A survey of maintenance models for multi-unit systems" by Cho and Parlar. This paper builds forth on the review article by Dekker et al.

  6. Optimization of maintenance periodicity of complex of NPP safety systems

    Kolykhanov, V.; Skalozubov, V.; Kovrigkin, Y.

    2006-01-01

    The analysis of the positive and negative aspects connected to maintenance of the safety systems equipment which basically is in a standby state is executed. Tests of systems provide elimination of the latent failures and raise their reliability. Poor quality of carrying out the tests can be a source of the subsequent failures. Therefore excess frequency of tests can result in reducing reliability of safety systems. The method of optimization of maintenance periodicity of the equipment taking into account factors of its reliability and restoration procedures quality is submitted. The unavailability factor is used as a criterion of optimization of maintenance periodicity. It is offered to use parameters of reliability of the equipment and each of safety systems of NPPs received at developing PSA. And it is offered to carry out the concordance of maintenance periodicity of systems within the NPP maintenance program taking into account a significance factor of the system received on the basis of the contribution of system in CDF. Basing on the submitted method the small computer code is developed. This code allows to calculate reliability factors of a separate safety system and to determine optimum maintenance periodicity of its equipment. Optimization of maintenance periodicity of a complex of safety systems is stipulated also. As an example results of optimization of maintenance periodicity at Zaporizhzhya NPP are presented. (author)

  7. Reliability-based performance simulation for optimized pavement maintenance

    Chou, Jui-Sheng; Le, Thanh-Son

    2011-01-01

    Roadway pavement maintenance is essential for driver safety and highway infrastructure efficiency. However, regular preventive maintenance and rehabilitation (M and R) activities are extremely costly. Unfortunately, the funds available for the M and R of highway pavement are often given lower priority compared to other national development policies, therefore, available funds must be allocated wisely. Maintenance strategies are typically implemented by optimizing only the cost whilst the reliability of facility performance is neglected. This study proposes a novel algorithm using multi-objective particle swarm optimization (MOPSO) technique to evaluate the cost-reliability tradeoff in a flexible maintenance strategy based on non-dominant solutions. Moreover, a probabilistic model for regression parameters is employed to assess reliability-based performance. A numerical example of a highway pavement project is illustrated to demonstrate the efficacy of the proposed MOPSO algorithms. The analytical results show that the proposed approach can help decision makers to optimize roadway maintenance plans. - Highlights: →A novel algorithm using multi-objective particle swarm optimization technique. → Evaluation of the cost-reliability tradeoff in a flexible maintenance strategy. → A probabilistic model for regression parameters is employed to assess reliability-based performance. → The proposed approach can help decision makers to optimize roadway maintenance plans.

  8. Reliability-based performance simulation for optimized pavement maintenance

    Chou, Jui-Sheng, E-mail: jschou@mail.ntust.edu.tw [Department of Construction Engineering, National Taiwan University of Science and Technology (Taiwan Tech), 43 Sec. 4, Keelung Rd., Taipei 106, Taiwan (China); Le, Thanh-Son [Department of Construction Engineering, National Taiwan University of Science and Technology (Taiwan Tech), 43 Sec. 4, Keelung Rd., Taipei 106, Taiwan (China)

    2011-10-15

    Roadway pavement maintenance is essential for driver safety and highway infrastructure efficiency. However, regular preventive maintenance and rehabilitation (M and R) activities are extremely costly. Unfortunately, the funds available for the M and R of highway pavement are often given lower priority compared to other national development policies, therefore, available funds must be allocated wisely. Maintenance strategies are typically implemented by optimizing only the cost whilst the reliability of facility performance is neglected. This study proposes a novel algorithm using multi-objective particle swarm optimization (MOPSO) technique to evaluate the cost-reliability tradeoff in a flexible maintenance strategy based on non-dominant solutions. Moreover, a probabilistic model for regression parameters is employed to assess reliability-based performance. A numerical example of a highway pavement project is illustrated to demonstrate the efficacy of the proposed MOPSO algorithms. The analytical results show that the proposed approach can help decision makers to optimize roadway maintenance plans. - Highlights: > A novel algorithm using multi-objective particle swarm optimization technique. > Evaluation of the cost-reliability tradeoff in a flexible maintenance strategy. > A probabilistic model for regression parameters is employed to assess reliability-based performance. > The proposed approach can help decision makers to optimize roadway maintenance plans.

  9. Optimal Maintenance for Stochastically Degrading Staellite Constellations

    Cook, Timothy J

    2005-01-01

    .... Previous work has developed a methodology to compute an optimal replacement policy for a satellite constellation in which satellites were viewed as binary entities, either operational or failed...

  10. Determination of Pareto frontier in multi-objective maintenance optimization

    Certa, Antonella; Galante, Giacomo; Lupo, Toni; Passannanti, Gianfranco

    2011-01-01

    The objective of a maintenance policy generally is the global maintenance cost minimization that involves not only the direct costs for both the maintenance actions and the spare parts, but also those ones due to the system stop for preventive maintenance and the downtime for failure. For some operating systems, the failure event can be dangerous so that they are asked to operate assuring a very high reliability level between two consecutive fixed stops. The present paper attempts to individuate the set of elements on which performing maintenance actions so that the system can assure the required reliability level until the next fixed stop for maintenance, minimizing both the global maintenance cost and the total maintenance time. In order to solve the previous constrained multi-objective optimization problem, an effective approach is proposed to obtain the best solutions (that is the Pareto optimal frontier) among which the decision maker will choose the more suitable one. As well known, describing the whole Pareto optimal frontier generally is a troublesome task. The paper proposes an algorithm able to rapidly overcome this problem and its effectiveness is shown by an application to a case study regarding a complex series-parallel system.

  11. CHALLENGES AND OPPORTUNITIES--INTEGRATED LIFE-CYCLE OPTIMIZATION INITIATIVES FOR THE HANFORD RIVER PROTECTION PROJECT--WASTE TREATMENT PLANT

    Auclair, K. D.

    2002-01-01

    This paper describes the ongoing integrated life-cycle optimization efforts to achieve both design flexibility and design stability for activities associated with the Waste Treatment Plant at Hanford. Design flexibility is required to support the Department of Energy Office of River Protection Balance of Mission objectives, and design stability to meet the Waste Treatment Plant construction and commissioning requirements in order to produce first glass in 2007. The Waste Treatment Plant is a large complex project that is driven by both technology and contractual requirements. It is also part of a larger overall mission, as a component of the River Protection Project, which is driven by programmatic requirements and regulatory, legal, and fiscal constraints. These issues are further complicated by the fact that both of the major contractors involved have a different contract type with DOE, and neither has a contract with the other. This combination of technical and programmatic drivers, constraints, and requirements will continue to provide challenges and opportunities for improvement and optimization. The Bechtel National, Inc. team is under contract to engineer, procure, construct, commission and test the Waste Treatment Plant on or ahead of schedule, at or under cost, and with a throughput capacity equal to or better than specified. The Department of Energy is tasked with the long term mission of waste retrieval, treatment, and disposal. While each mission is a compliment and inextricably linked to one another, they are also at opposite ends of the spectrum, in terms of expectations of one another. These mission requirements, that are seemingly in opposition to one another, pose the single largest challenge and opportunity for optimization: one of balance. While it is recognized that design maturation and optimization are the normal responsibility of any engineering firm responsible for any given project, the aspects of integrating requirements and the management

  12. Development of a methodology for maintenance optimization at Kozloduy NPP

    Kitchev, E.

    1997-01-01

    The paper presents the overview of a project for development of an applicable strategy and methods for Kozloduy NPP (KNPP) to optimize its maintenance program in order to meet the current risk based maintenance requirements. The strategy in a format of Integrated Maintenance Program (IMP) manual will define the targets of the optimization process, the major stages and elements of this process and their relationships. IMP embodies the aspects of the US NRC Maintenance Rule compliance and facilitates the integration of KNPP programs and processes which impact the plant maintenance and safety. The methods in a format of IMP Instructions (IM-PI) will define how the different IMP stages can be implemented and the IMP targets can be achieved at KNPP environment. (author). 8 refs

  13. Maintenance modeling and optimization integrating human and material resources

    Martorell, S.; Villamizar, M.; Carlos, S.; Sanchez, A.

    2010-01-01

    Maintenance planning is a subject of concern to many industrial sectors as plant safety and business depend on it. Traditionally, the maintenance planning is formulated in terms of a multi-objective optimization (MOP) problem where reliability, availability, maintainability and cost (RAM+C) act as decision criteria and maintenance strategies (i.e. maintenance tasks intervals) act as the only decision variables. However the appropriate development of each maintenance strategy depends not only on the maintenance intervals but also on the resources (human and material) available to implement such strategies. Thus, the effect of the necessary resources on RAM+C needs to be modeled and accounted for in formulating the MOP affecting the set of objectives and constraints. In this paper RAM+C models to explicitly address the effect of human resources and material resources (spare parts) on RAM+C criteria are proposed. This extended model allows accounting for explicitly how the above decision criteria depends on the basic model parameters representing the type of strategies, maintenance intervals, durations, human resources and material resources. Finally, an application case is performed to optimize the maintenance plan of a motor-driven pump equipment considering as decision variables maintenance and test intervals and human and material resources.

  14. Maintenance modeling and optimization integrating human and material resources

    Martorell, S., E-mail: smartore@iqn.upv.e [Dpto. Ingenieria Quimica y Nuclear, Universidad Politecnica Valencia (Spain); Villamizar, M.; Carlos, S. [Dpto. Ingenieria Quimica y Nuclear, Universidad Politecnica Valencia (Spain); Sanchez, A. [Dpto. Estadistica e Investigacion Operativa Aplicadas y Calidad, Universidad Politecnica Valencia (Spain)

    2010-12-15

    Maintenance planning is a subject of concern to many industrial sectors as plant safety and business depend on it. Traditionally, the maintenance planning is formulated in terms of a multi-objective optimization (MOP) problem where reliability, availability, maintainability and cost (RAM+C) act as decision criteria and maintenance strategies (i.e. maintenance tasks intervals) act as the only decision variables. However the appropriate development of each maintenance strategy depends not only on the maintenance intervals but also on the resources (human and material) available to implement such strategies. Thus, the effect of the necessary resources on RAM+C needs to be modeled and accounted for in formulating the MOP affecting the set of objectives and constraints. In this paper RAM+C models to explicitly address the effect of human resources and material resources (spare parts) on RAM+C criteria are proposed. This extended model allows accounting for explicitly how the above decision criteria depends on the basic model parameters representing the type of strategies, maintenance intervals, durations, human resources and material resources. Finally, an application case is performed to optimize the maintenance plan of a motor-driven pump equipment considering as decision variables maintenance and test intervals and human and material resources.

  15. Equipment reliability process improvement and preventive maintenance optimization

    Darragi, M.; Georges, A.; Vaillancourt, R.; Komljenovic, D.; Croteau, M.

    2004-01-01

    The Gentilly-2 Nuclear Power Plant wants to optimize its preventive maintenance program through an Integrated Equipment Reliability Process. All equipment reliability related activities should be reviewed and optimized in a systematic approach especially for aging plants such as G2. This new approach has to be founded on best practices methods with the purpose of the rationalization of the preventive maintenance program and the performance monitoring of on-site systems, structures and components (SSC). A rational preventive maintenance strategy is based on optimized task scopes and frequencies depending on their applicability, critical effects on system safety and plant availability as well as cost-effectiveness. Preventive maintenance strategy efficiency is systematically monitored through degradation indicators. (author)

  16. Maintenance optimization in nuclear power plants through genetic algorithms

    Munoz, A.; Martorell, S.; Serradell, V.

    1999-01-01

    Establishing suitable scheduled maintenance tasks leads to optimizing the reliability of nuclear power plant safety systems. The articles addresses this subject, whilst endeavoring to tackle an overall optimization process for component availability and safety systems through the use of genetic algorithms. (Author) 20 refs

  17. Pavement maintenance optimization model using Markov Decision Processes

    Mandiartha, P.; Duffield, C. F.; Razelan, I. S. b. M.; Ismail, A. b. H.

    2017-09-01

    This paper presents an optimization model for selection of pavement maintenance intervention using a theory of Markov Decision Processes (MDP). There are some particular characteristics of the MDP developed in this paper which distinguish it from other similar studies or optimization models intended for pavement maintenance policy development. These unique characteristics include a direct inclusion of constraints into the formulation of MDP, the use of an average cost method of MDP, and the policy development process based on the dual linear programming solution. The limited information or discussions that are available on these matters in terms of stochastic based optimization model in road network management motivates this study. This paper uses a data set acquired from road authorities of state of Victoria, Australia, to test the model and recommends steps in the computation of MDP based stochastic optimization model, leading to the development of optimum pavement maintenance policy.

  18. A probabilistic computational framework for bridge network optimal maintenance scheduling

    Bocchini, Paolo; Frangopol, Dan M.

    2011-01-01

    This paper presents a probabilistic computational framework for the Pareto optimization of the preventive maintenance applications to bridges of a highway transportation network. The bridge characteristics are represented by their uncertain reliability index profiles. The in/out of service states of the bridges are simulated taking into account their correlation structure. Multi-objective Genetic Algorithms have been chosen as numerical tool for the solution of the optimization problem. The design variables of the optimization are the preventive maintenance schedules of all the bridges of the network. The two conflicting objectives are the minimization of the total present maintenance cost and the maximization of the network performance indicator. The final result is the Pareto front of optimal solutions among which the managers should chose, depending on engineering and economical factors. A numerical example illustrates the application of the proposed approach.

  19. AN OPTIMAL MAINTENANCE MANAGEMENT MODEL FOR AIRPORT CONCRETE PAVEMENT

    Shimomura, Taizo; Fujimori, Yuji; Kaito, Kiyoyuki; Obama, Kengo; Kobayashi, Kiyoshi

    In this paper, an optimal management model is formulated for the performance-based rehabilitation/maintenance contract for airport concrete pavement, whereby two types of life cycle cost risks, i.e., ground consolidation risk and concrete depreciation risk, are explicitly considered. The non-homogenous Markov chain model is formulated to represent the deterioration processes of concrete pavement which are conditional upon the ground consolidation processes. The optimal non-homogenous Markov decision model with multiple types of risk is presented to design the optimal rehabilitation/maintenance plans. And the methodology to revise the optimal rehabilitation/maintenance plans based upon the monitoring data by the Bayesian up-to-dating rules. The validity of the methodology presented in this paper is examined based upon the case studies carried out for the H airport.

  20. Optimal maintenance policies in incomplete repair models

    Kahle, Waltraud

    2007-01-01

    We consider an incomplete repair model, that is, the impact of repair is not minimal as in the homogeneous Poisson process and not 'as good as new' as in renewal processes but lies between these boundary cases. The repairs are assumed to impact the failure intensity following a virtual age process of the general form proposed by Kijima. In previous works field data from an industrial setting were used to fit several models. In most cases the estimated rate of occurrence of failures was that of an underlying exponential distribution of the time between failures. In this paper, it is shown that there exist maintenance schedules under which the failure behavior of the failure-repair process becomes a homogeneous Poisson process

  1. The use of lifetime functions in the optimization of interventions on existing bridges considering maintenance and failure costs

    Yang, Seung-Ie [Department of Civil, Enviromental, and Architectural Enginnering, University of Colorado, Campus Box 428, Boulder, CO 80309-0428 (United States)]. E-mail: yangsione@dreamwiz.com; Frangopol, Dan M. [Department of Civil, Enviromental, and Architectural Enginnering, University of Colorado, Campus Box 428, Boulder, CO 80309-0428 (United States)]. E-mail: dan.frangopol@colorado.edu; Kawakami, Yoriko [Hanshin Expressway Public Corporation, Kobe Maintenance Department, 16-1 Shinko-cho Chuo-ku Kobe City, Hyogo, 650-0041 (Japan)]. E-mail: yoriko-kawakami@hepc.go.jp; Neves, Luis C. [Department of Civil, Enviromental, and Architectural Enginnering, University of Colorado, Campus Box 428, Boulder, CO 80309-0428 (United States)]. E-mail: lneves@civil.uminho.pt

    2006-06-15

    In the last decade, it became clear that life-cycle cost analysis of existing civil infrastructure must be used to optimally manage the growing number of aging and deteriorating structures. The uncertainties associated with deteriorating structures require the use of probabilistic methods to properly evaluate their lifetime performance. In this paper, the deterioration and the effect of maintenance actions are analyzed considering the performance of existing structures characterized by lifetime functions. These functions allow, in a simple manner, the consideration of the effect of aging on the decrease of the probability of survival of a structure, as well as the effect of maintenance actions. Models for the effects of proactive and reactive preventive maintenance, and essential maintenance actions are presented. Since the probability of failure is different from zero during the entire service life of a deteriorating structure and depends strongly on the maintenance strategy, the cost of failure is included in this analysis. The failure of one component in a structure does not usually lead to failure of the structure and, as a result, the safety of existing structures must be analyzed using a system reliability framework. The optimization consists of minimizing the sum of the cumulative maintenance and expected failure cost during the prescribed time horizon. Two examples of application of the proposed methodology are presented. In the first example, the sum of the maintenance and failure costs of a bridge in Colorado is minimized considering essential maintenance only and a fixed minimum acceptable probability of failure. In the second example, the expected lifetime cost, including maintenance and expected failure costs, of a multi-girder bridge is minimized considering reactive preventive maintenance actions.

  2. The use of lifetime functions in the optimization of interventions on existing bridges considering maintenance and failure costs

    Yang, Seung-Ie; Frangopol, Dan M.; Kawakami, Yoriko; Neves, Luis C.

    2006-01-01

    In the last decade, it became clear that life-cycle cost analysis of existing civil infrastructure must be used to optimally manage the growing number of aging and deteriorating structures. The uncertainties associated with deteriorating structures require the use of probabilistic methods to properly evaluate their lifetime performance. In this paper, the deterioration and the effect of maintenance actions are analyzed considering the performance of existing structures characterized by lifetime functions. These functions allow, in a simple manner, the consideration of the effect of aging on the decrease of the probability of survival of a structure, as well as the effect of maintenance actions. Models for the effects of proactive and reactive preventive maintenance, and essential maintenance actions are presented. Since the probability of failure is different from zero during the entire service life of a deteriorating structure and depends strongly on the maintenance strategy, the cost of failure is included in this analysis. The failure of one component in a structure does not usually lead to failure of the structure and, as a result, the safety of existing structures must be analyzed using a system reliability framework. The optimization consists of minimizing the sum of the cumulative maintenance and expected failure cost during the prescribed time horizon. Two examples of application of the proposed methodology are presented. In the first example, the sum of the maintenance and failure costs of a bridge in Colorado is minimized considering essential maintenance only and a fixed minimum acceptable probability of failure. In the second example, the expected lifetime cost, including maintenance and expected failure costs, of a multi-girder bridge is minimized considering reactive preventive maintenance actions

  3. Maintenance and test strategies to optimize NPP equipment performance

    Mayer, S.; Tomic, B.

    2000-01-01

    This paper proposes an approach to maintenance optimization of nuclear power plant components, which can help to increase both safety and availability. In order to evaluate the benefits of preventive maintenance on a quantitative basis, a software code has been developed for component performance and reliability simulation of safety related nuclear power plant equipment. A three state Markov model will be introduced, considering a degraded state in addition to an operational state and a failed state. (author)

  4. Optimization and maintenance tests considering multiple failure modes, aging and imperfect maintenance

    Martorell, S.; Marton, I.; Sanchez, A.; Carlos, S.

    2014-01-01

    The paper focuses on the optimization of the test and maintenance intervals under the criteria of unavailability or cost including the effect of the aging of the components and models of imperfect maintenance. The results obtained in the case of application, which focuses on a system of safety of a nuclear power station, show differences, mainly in the outage when you consider the aging. (Author)

  5. Maintenance cost optimization in condition based maintenance: a case study for critical facilities

    Filippo De Carlo; Maria Antonietta Arleo

    2013-01-01

    The increasing availability required to industrial plants and the limited budget often existing to assure it, require a careful formulation of maintenance optimization models. This need is primary for process plants, for which minimization of stops and maximization of their availability, are essential for ensuring targeted production and, therefore, profitability. In this context, the choice of the maintenance strategy is hence fundamental, depending on the system features and then on the eff...

  6. Multi-objective group scheduling optimization integrated with preventive maintenance

    Liao, Wenzhu; Zhang, Xiufang; Jiang, Min

    2017-11-01

    This article proposes a single-machine-based integration model to meet the requirements of production scheduling and preventive maintenance in group production. To describe the production for identical/similar and different jobs, this integrated model considers the learning and forgetting effects. Based on machine degradation, the deterioration effect is also considered. Moreover, perfect maintenance and minimal repair are adopted in this integrated model. The multi-objective of minimizing total completion time and maintenance cost is taken to meet the dual requirements of delivery date and cost. Finally, a genetic algorithm is developed to solve this optimization model, and the computation results demonstrate that this integrated model is effective and reliable.

  7. A PSO approach for preventive maintenance scheduling optimization

    Pereira, C.M.N.A.; Lapa, C.M.F.; Mol, A.C.A.; Luz, A.F. da

    2009-01-01

    This work presents a Particle Swarm Optimization (PSO) approach for preventive maintenance policy optimization, focused in reliability and cost. The probabilistic model for reliability and cost evaluation is developed in such a way that flexible intervals between maintenance are allowed. As PSO is skilled for realcoded continuous spaces, a non-conventional codification has been developed in order to allow PSO to solve scheduling problems (which is discrete) with variable number of maintenance interventions. In order to evaluate the proposed methodology, the High Pressure Injection System (HPIS) of a typical 4-loop PWR has been considered. Results demonstrate ability in finding optimal solutions, for which expert knowledge had to be automatically discovered by PSO. (author)

  8. Global Crisis as Enterprise Software Motivator: from Lifecycle Optimization to Efficient Implementation Series

    Sergey V. Zykov

    2012-04-01

    Full Text Available It is generally known that software system development lifecycle (SSDL should be managed adequately. The global economy crisis and subsequent depression have taught us certain lessons on the subject, which is so vital for enterprises. The paper presents the adaptive methodology of enterprise SSDL, which allows to avoid "local crises" while producing large-scale software. The methodology is based on extracting common ERP module level patterns and applying them to series of heterogeneous implementations. The approach includes a lifecycle model, which extends conventional spiral model by formal data representation/management models and DSL-based "low-level" CASE tools supporting the formalisms. The methodology has been successfully implemented as a series of portal-based ERP systems in ITERA oil-and-gas corporation, and in a number of trading/banking enterprise applications for other enterprises. Semantic network-based airline dispatch system, and a 6D-model-driven nuclear power plant construction support system are currently in progress. Combining various SSDL models is discussed. Terms-and-cost reduction factors are examined. Correcting SSDL according to project size and scope is overviewed. The so-called “human factor errors” resulting from non-systematic SSDL approach, and their influencing crisis and depression, are analyzed. The ways to systematic and efficient SSDL are outlined. Troubleshooting advises are given for the problems concerned.

  9. Airline Maintenance Manpower Optimization from the De Novo Perspective

    Liou, James J. H.; Tzeng, Gwo-Hshiung

    Human resource management (HRM) is an important issue for today’s competitive airline marketing. In this paper, we discuss a multi-objective model designed from the De Novo perspective to help airlines optimize their maintenance manpower portfolio. The effectiveness of the model and solution algorithm is demonstrated in an empirical study of the optimization of the human resources needed for airline line maintenance. Both De Novo and traditional multiple objective programming (MOP) methods are analyzed. A comparison of the results with those of traditional MOP indicates that the proposed model and solution algorithm does provide better performance and an improved human resource portfolio.

  10. Fuel Optimization for Low Earth Orbit Maintenance

    Yong Jae Park

    2008-06-01

    Full Text Available The resolution of Earth images taken from a satellite has close relation with satellite's altitude. If a satellite has lower altitude, it gets a picture having better resolution. However the satellite will be exposed to heavier air drag and will spend more fuel to maintain its altitude for a desired mission. Therefore, in this study, the required fuel to maintain very low earth orbit(LEO with severe air drag is analyzed using optimization method such as collocation method. The required fuel to maintain the low altitude has significantly increased as the mission altitude is lowered and the solar activity is maximized. This study also shows that the fuel reduced by increasing the period of the satellite maneuver is very small, and that slightly increasing the satellite's mission altitude is much effective in reducing the amount of fuel to maintain its altitude. The calculated fuel to maintain very low earth orbit in this study would give useful information in planning the budget of fuel and cost for LEO satellites.

  11. Optimizing stormwater treatment practices a handbook of assessment and maintenance

    Erickson, Andrew J; Gulliver, John S

    2013-01-01

    Optimizing Stormwater Treatment Practices: A Handbook of Assessment and Maintenance provides the information necessary for developing and operating an effective maintenance program for stormwater treatment. The book offers instructions on how to measure the level of performance of stormwater treatment practices directly and bases proposed maintenance schedules on actual performance and historical maintenance efforts and costs. The inspection methods, which are proven in the field and have been implemented successfully, are necessary as regulatory agencies are demanding evaluations of the performance of stormwater treatment practices. The authors have developed a three-tiered approach that offers readers a standard protocol for how to determine the effectiveness of stormwater treatment practices currently in place. This book also: Provides a standard protocol for how to determine the effectiveness of stormwater treatment practices Assists readers with identifying which assessment techniques to use for stormwa...

  12. Effective computing algorithm for maintenance optimization of highly reliable systems

    Briš, R.; Byczanski, Petr

    2013-01-01

    Roč. 109, č. 1 (2013), s. 77-85 ISSN 0951-8320 R&D Projects: GA MŠk(CZ) ED1.1.00/02.0070 Institutional support: RVO:68145535 Keywords : exact computing * maintenance * optimization * unavailability Subject RIV: BA - General Mathematics Impact factor: 2.048, year: 2013 http://www.sciencedirect.com/science/article/pii/S0951832012001639

  13. Identification of Optimal Preventive Maintenance Decisions for Composite Components

    Laks, P.; Verhagen, W.J.C.; Gherman, B.; Porumbel, I.

    2018-01-01

    This research proposes a decision support tool which identifies cost-optimal maintenance decisions for a given planning period. Simultaneously, the reliability state of the component is kept at or below a given reliability threshold: a failure limit policy applies. The tool is developed to support

  14. Optimal Tax-Transfer Policies, Life-Cycle Labour Supply and Present-Biased Preferences

    Gunnersen, Lasse Frisgaard; Rasmussen, Bo Sandemann

    Using a two-period model with two types of agents that are characterized by present-biased preferences second-best optimal tax-transfer policies are considered. The paternalistic optimal tax-transfer policy has two main concerns: Income redistribution from high to low ability households...... consequences not only for optimal subsidies to savings but also for optimal marginal income taxes....

  15. Information-Based Maintenance Optimization with Focus on Predictive Maintenance (Informatiegebaseerde onderhoudsoptimalisatie met focus op predictief onderhoud)

    Van Horenbeek, Adriaan

    2013-01-01

    This dissertation presents an information-based maintenance optimization methodology for physical assets; with focus on, but not limited to, predictive maintenance (PdM). The overall concept of information-based maintenance is that of updating maintenance decisions based on evolving knowledge of operation history and anticipated usage of the machinery, as well as the physics and dynamics of material degradation in critical machinery components. Within this concept, predictive maintenance is a...

  16. Optimal interval for major maintenance actions in electricity distribution networks

    Louit, Darko; Pascual, Rodrigo [Centro de Mineria, Pontificia Universidad Catolica de Chile, Av. Vicuna MacKenna, 4860 Santiago (Chile); Banjevic, Dragan [Centre for Maintenance Optimization and Reliability Engineering, University of Toronto, 5 King' s College Rd., Toronto, Ontario (Canada)

    2009-09-15

    Many systems require the periodic undertaking of major (preventive) maintenance actions (MMAs) such as overhauls in mechanical equipment, reconditioning of train lines, resurfacing of roads, etc. In the long term, these actions contribute to achieving a lower rate of occurrence of failures, though in many cases they increase the intensity of the failure process shortly after performed, resulting in a non-monotonic trend for failure intensity. Also, in the special case of distributed assets such as communications and energy networks, pipelines, etc., it is likely that the maintenance action takes place sequentially over an extended period of time, implying that different sections of the network underwent the MMAs at different periods. This forces the development of a model based on a relative time scale (i.e. time since last major maintenance event) and the combination of data from different sections of a grid, under a normalization scheme. Additionally, extended maintenance times and sequential execution of the MMAs make it difficult to identify failures occurring before and after the preventive maintenance action. This results in the loss of important information for the characterization of the failure process. A simple model is introduced to determine the optimal MMA interval considering such restrictions. Furthermore, a case study illustrates the optimal tree trimming interval around an electricity distribution network. (author)

  17. Joint optimization of maintenance, buffers and machines in manufacturing lines

    Nahas, Nabil; Nourelfath, Mustapha

    2018-01-01

    This article considers a series manufacturing line composed of several machines separated by intermediate buffers of finite capacity. The goal is to find the optimal number of preventive maintenance actions performed on each machine, the optimal selection of machines and the optimal buffer allocation plan that minimize the total system cost, while providing the desired system throughput level. The mean times between failures of all machines are assumed to increase when applying periodic preventive maintenance. To estimate the production line throughput, a decomposition method is used. The decision variables in the formulated optimal design problem are buffer levels, types of machines and times between preventive maintenance actions. Three heuristic approaches are developed to solve the formulated combinatorial optimization problem. The first heuristic consists of a genetic algorithm, the second is based on the nonlinear threshold accepting metaheuristic and the third is an ant colony system. The proposed heuristics are compared and their efficiency is shown through several numerical examples. It is found that the nonlinear threshold accepting algorithm outperforms the genetic algorithm and ant colony system, while the genetic algorithm provides better results than the ant colony system for longer manufacturing lines.

  18. Optimal Inspection and Maintenance Strategies for Structural Systems

    Sommer, A. M.

    The aim of this thesis is to give an overview of conventional and optimal reliability-based inspection and maintenance strategies and to examine for specific structures how the cost can be reduced and/or the safety can be improved by using optimal reliability-based inspection strategies....... For structures with several almost similar components it is suggested that individual inspection strategies should be determined for each component or a group of components based on the reliability of the actual component. The benefit of this procedure is assessed in connection with the structures considered....... Furthermore, in relation to the calculations performed the intention is to modify an existing program for determination of optimal inspection strategies. The main purpose of inspection and maintenance of structural systems is to prevent or delay damage or deterioration to protect people, environment...

  19. Maintenance optimization of the Ignalina NPP safety systems

    Zuokas, D.; Augutis, J.

    2000-01-01

    This paper represents some theses and mathematical approach to optimization of technical specification problems of the diesel generators system (DGS) at the Ignalina NPP (INPP) in Lithuania. Analysis unites three chapters, each attributed to the solving of related problems: dependency of the Core Damage Frequency (CDF) on DGS test interval (Chapter 2), analysis and comparison of two different maintenance strategies for DGS (Chapter 3), DGS test interval's optimisation (averaged loss function minimisation) taking into consideration maintenance and DGS failure's consequence costs (Chapter 4). The mathematical model was developed which lets to estimate DGS failure probability, the averaged loss function value and study the influence of different parameters into final results. (author)

  20. Novel pathways for fuels and lubricants from biomass optimized using life-cycle greenhouse gas assessment

    Balakrishnan, Madhesan; Sacia, Eric R.; Sreekumar, Sanil; Gunbas, Gorkem; Gokhale, Amit A.; Scown, Corinne D.; Toste, F. Dean; Bell, Alexis T.

    2015-01-01

    Decarbonizing the transportation sector is critical to achieving global climate change mitigation. Although biofuels will play an important role in conventional gasoline and diesel applications, bioderived solutions are particularly important in jet fuels and lubricants, for which no other viable renewable alternatives exist. Producing compounds for jet fuel and lubricant base oil applications often requires upgrading fermentation products, such as alcohols and ketones, to reach the appropriate molecular-weight range. Ketones possess both electrophilic and nucleophilic functionality, which allows them to be used as building blocks similar to alkenes and aromatics in a petroleum refining complex. Here, we develop a method for selectively upgrading biomass-derived alkyl methyl ketones with >95% yields into trimer condensates, which can then be hydrodeoxygenated in near-quantitative yields to give a new class of cycloalkane compounds. The basic chemistry developed here can be tailored for aviation fuels as well as lubricants by changing the production strategy. We also demonstrate that a sugarcane biorefinery could use natural synergies between various routes to produce a mixture of lubricant base oils and jet fuels that achieve net life-cycle greenhouse gas savings of up to 80%. PMID:26056307

  1. An approach to maintenance optimization where safety issues are important

    Vatn, Jorn, E-mail: jorn.vatn@ntnu.n [NTNU, Production and Quality Engineering, 7491 Trondheim (Norway); Aven, Terje [University of Stavanger (Norway)

    2010-01-15

    The starting point for this paper is a traditional approach to maintenance optimization where an object function is used for optimizing maintenance intervals. The object function reflects maintenance cost, cost of loss of production/services, as well as safety costs, and is based on a classical cost-benefit analysis approach where a value of prevented fatality (VPF) is used to weight the importance of safety. However, the rationale for such an approach could be questioned. What is the meaning of such a VPF figure, and is it sufficient to reflect the importance of safety by calculating the expected fatality loss VPF and potential loss of lives (PLL) as being done in the cost-benefit analyses? Should the VPF be the same number for all type of accidents, or should it be increased in case of multiple fatality accidents to reflect gross accident aversion? In this paper, these issues are discussed. We conclude that we have to see beyond the expected values in situations with high safety impacts. A framework is presented which opens up for a broader decision basis, covering considerations on the potential for gross accidents, the type of uncertainties and lack of knowledge of important risk influencing factors. Decisions with a high safety impact are moved from the maintenance department to the 'Safety Board' for a broader discussion. In this way, we avoid that the object function is used in a mechanical way to optimize the maintenance and important safety-related decisions are made implicit and outside the normal arena for safety decisions, e.g. outside the traditional 'Safety Board'. A case study from the Norwegian railways is used to illustrate the discussions.

  2. An approach to maintenance optimization where safety issues are important

    Vatn, Jorn; Aven, Terje

    2010-01-01

    The starting point for this paper is a traditional approach to maintenance optimization where an object function is used for optimizing maintenance intervals. The object function reflects maintenance cost, cost of loss of production/services, as well as safety costs, and is based on a classical cost-benefit analysis approach where a value of prevented fatality (VPF) is used to weight the importance of safety. However, the rationale for such an approach could be questioned. What is the meaning of such a VPF figure, and is it sufficient to reflect the importance of safety by calculating the expected fatality loss VPF and potential loss of lives (PLL) as being done in the cost-benefit analyses? Should the VPF be the same number for all type of accidents, or should it be increased in case of multiple fatality accidents to reflect gross accident aversion? In this paper, these issues are discussed. We conclude that we have to see beyond the expected values in situations with high safety impacts. A framework is presented which opens up for a broader decision basis, covering considerations on the potential for gross accidents, the type of uncertainties and lack of knowledge of important risk influencing factors. Decisions with a high safety impact are moved from the maintenance department to the 'Safety Board' for a broader discussion. In this way, we avoid that the object function is used in a mechanical way to optimize the maintenance and important safety-related decisions are made implicit and outside the normal arena for safety decisions, e.g. outside the traditional 'Safety Board'. A case study from the Norwegian railways is used to illustrate the discussions.

  3. Estimation of component redundancy in optimal age maintenance

    Siopa, Jorge; Garção, José; Silva, Júlio

    2012-01-01

    The classical Optimal Age-Replacement defines the maintenance strategy based on the equipment failure consequences. For severe consequences an early equipment replacement is recommended. For minor consequences the repair after failure is proposed. One way of reducing the failure consequences is the use of redundancies, especially if the equipment failure rate is decreasing over time, since in this case the preventive replacement does not reduce the risk of failure. The estimation of an ac...

  4. Allowed outage time for test and maintenance - Optimization of safety

    Cepin, M.; Mavko, B.

    1997-01-01

    The main objective of the project is the development and application of methodologies for improvement and optimization of test and maintenance activities for safety related equipment in NPPs on basis of their enhanced safety. The probabilistic safety assessment serves as a base, which does not mean the replacement of the deterministic analyses but the consideration of probabilistic safety assessment results as complement to deterministic results. 15 refs, 2 figs

  5. Optimal Maintenance of a Production System with Intermediate Buffers

    Constantinos C. Karamatsoukis

    2012-01-01

    Full Text Available We consider a production-inventory system that consists of an input-generating installation, a production unit and L intermediate buffers. It is assumed that the installation transfers the raw material to buffer and the production unit pulls the raw material from buffer We consider the problem of the optimal preventive maintenance of the installation if the installation deteriorates stochastically with usage and the production unit is always in operative condition. We also consider the problem of the optimal preventive maintenance of the production unit if the production unit deteriorates stochastically with usage and the installation is always in operative condition. Under a suitable cost structure and for given contents of the buffers, it is proved that the average-cost optimal policy for the first (second problem initiates a preventive maintenance of the installation (production unit if and only if the degree of deterioration of the installation (production unit exceeds some critical level. Numerical results are presented for both problems.

  6. Initiating stochastic maintenance optimization at Candu Power Plants

    Doyle, E.K.

    2003-01-01

    As previously reported at ICONE 6 in New Orleans (1996), the use of various innovative maintenance optimization techniques at Bruce has lead to cost effective preventive maintenance applications for complex systems. Further cost refinement of the station maintenance strategy is being evaluated via the applicability of statistical analysis of historical failure data. Since the statistical evaluation was initiated in 1999 significant progress has been made in demonstrating the viability of stochastic methods in Candu maintenance. Some of the relevant results were presented at ICONE 10 in Washington DC (2002). Success with the graphical displays and the relatively easy to implement stochastic computer programs was sufficient to move the program along to the next significant phase. This next phase consists of investigating the validity of using subjective elicitation techniques to obtain component lifetime distributions. This technique provides access to the elusive failure statistics, the lack of which is often referred to in the literature as the principle impediment preventing the use of stochastic methods in large industry. At the same time the technique allows very valuable information to be captured from the fast retiring 'baby boom generation'. Initial indications have been quite positive. (author)

  7. Solving complex maintenance planning optimization problems using stochastic simulation and multi-criteria fuzzy decision making

    Tahvili, Sahar; Österberg, Jonas; Silvestrov, Sergei; Biteus, Jonas

    2014-01-01

    One of the most important factors in the operations of many cooperations today is to maximize profit and one important tool to that effect is the optimization of maintenance activities. Maintenance activities is at the largest level divided into two major areas, corrective maintenance (CM) and preventive maintenance (PM). When optimizing maintenance activities, by a maintenance plan or policy, we seek to find the best activities to perform at each point in time, be it PM or CM. We explore the use of stochastic simulation, genetic algorithms and other tools for solving complex maintenance planning optimization problems in terms of a suggested framework model based on discrete event simulation

  8. Solving complex maintenance planning optimization problems using stochastic simulation and multi-criteria fuzzy decision making

    Tahvili, Sahar [Mälardalen University (Sweden); Österberg, Jonas; Silvestrov, Sergei [Division of Applied Mathematics, Mälardalen University (Sweden); Biteus, Jonas [Scania CV (Sweden)

    2014-12-10

    One of the most important factors in the operations of many cooperations today is to maximize profit and one important tool to that effect is the optimization of maintenance activities. Maintenance activities is at the largest level divided into two major areas, corrective maintenance (CM) and preventive maintenance (PM). When optimizing maintenance activities, by a maintenance plan or policy, we seek to find the best activities to perform at each point in time, be it PM or CM. We explore the use of stochastic simulation, genetic algorithms and other tools for solving complex maintenance planning optimization problems in terms of a suggested framework model based on discrete event simulation.

  9. A Novel Approach for Risk Minimization in Life-Cycle Oil Production Optimization

    Capolei, Andrea; Christiansen, Lasse Hjuler; Jørgensen, John Bagterp

    2017-01-01

    The oil research community has invested much effort into computer aided optimization to enhance oil recovery. While simulation studies have demonstrated the potential of model-based technology to improve industrial standards, the largely unknown geology of subsurface reservoirs limits application...

  10. Optimizing Maintenance of Constraint-Based Database Caches

    Klein, Joachim; Braun, Susanne

    Caching data reduces user-perceived latency and often enhances availability in case of server crashes or network failures. DB caching aims at local processing of declarative queries in a DBMS-managed cache close to the application. Query evaluation must produce the same results as if done at the remote database backend, which implies that all data records needed to process such a query must be present and controlled by the cache, i. e., to achieve “predicate-specific” loading and unloading of such record sets. Hence, cache maintenance must be based on cache constraints such that “predicate completeness” of the caching units currently present can be guaranteed at any point in time. We explore how cache groups can be maintained to provide the data currently needed. Moreover, we design and optimize loading and unloading algorithms for sets of records keeping the caching units complete, before we empirically identify the costs involved in cache maintenance.

  11. The maintenance optimization of structural components in nuclear power plants

    Bryla, P.; Ardorino, F.; Aufort, P.; Jacquot, J.P.; Magne, L.; Pitner, P.; Verite, B.; Villain, B.; Monnier, B.

    1997-10-01

    An optimization process, called 'OMF-Structures', is developed by Electricite de France (EDF) in order to extend the current 'OMF' Reliability Centered Maintenance to piping structural components. The Auxiliary Feedwater System of a 900 MW French nuclear plant has been studied in order to lay the foundations of the method. This paper presents the currently proposed principles of the process. The principles of the OMF-Structures process include 'Risk-Based Inspection' concepts within an RCM process. Two main phases are identified: The purpose of the first phase is to select the risk-significant failure modes and associated elements. This phase consists of two major steps: potential consequences evaluation and reliability performance evaluation. The second phase consists of the definition of preventive maintenance programs for piping elements that are associated with risk-significant failure modes. (author)

  12. Reducing Costs and Increasing Productivity in Ship Maintenance Using Product Lifecycle Management, 3D Laser Scanning and 3D Printing

    2014-03-01

    parts and to replace balance material on components that are reassembled, rebalanced , and reused, like the external air seal edge of a gas turbine...Komoroski, Housel, Hom, and Mun (2006) began by discussing the nature of portfolio management in the military and measuring value in the public sector...at the sub-corporate level. In addition, KVA + RO can provide risk mitigation and portfolio optimization. Komoroski et al. (2006) initiated the

  13. Comparing effectiveness and efficiency in technical specifications and maintenance optimization

    Martorell, Sebastian; Sanchez, Ana; Carlos, Sofia; Serradell, Vicente

    2002-01-01

    Optimization of technical specification requirements and maintenance (TS and M) has been found interesting from the very beginning at Nuclear Power Plants (NPPs). However, the resolution of such a kind of optimization problem has been limited often to focus only on individual TS and M-related parameters (STI, AOT, PM frequency, etc.) and/or adopting an individual optimization criterion (availability, costs, plant risks, etc.). Nevertheless, a number of reasons exist (e.g. interaction, similar scope, etc.) that justify the interest to focus on the coordinated optimization of all of the relevant TS and M-related parameters based on multiple criteria. The purpose of this paper is on signifying benefits and improvement areas in performing the coordinated optimization of TS and M through reviewing the effectiveness and efficiency of common strategies for optimizing TS and M at system level. A case of application is provided for a stand-by safety-related system to demonstrate the basic procedure and to extract a number of conclusions and recommendations from the results achieved. Thus, it is concluded that the optimized values depend on the particular TS and M-related parameters being involved and the solutions with the largest benefit (minimum risk or minimum cost) are achieved when considering the simultaneous optimization of all of them, although increased computational resources are also required. Consequently, it is necessary to analyze not only the value reached but also the performance of the optimization procedure through effectiveness and efficiency measures which lead to recommendations on potential improvement areas

  14. Optimization potential in maintenance; Optimierungspotenzial in der Instandhaltung

    Janisch, H. [EnBW Kraftwerke AG, Kernkraftwerk Philippsburg (Germany)

    2001-04-01

    Also in the future, the supreme goal of nuclear power plant operation is going to be plant safety. At the same time, the economic component must be taken into account, which has become more important as a consequence of the deregulation in the electricity market. Until now, the electricity generating costs in nuclear power plants have been optimized by increases in electricity generation, and by high plant availabilities in terms of time and capacity. However, these capacity-based influences on the generating costs practically have been exploited to the full extent possible because of the high plant reliability reached. This makes the cost term the focal point in all optimization efforts, i.e. in existing nuclear power plants especially the maintenance costs. At the present high level of safety, which is going to develop even further, growing operating experience will allow a change to be made from preventive maintenance to cost-optimized state-oriented maintenance strategies. Other measures of advanced maintenance strategies are seen in the fields of work organization, personnel management, and personnel and plant use planning for more than one site. Important components in this effort are IT-based plant management systems allowing the complex problems to be planned, executed, controlled, and analyzed. All these measures serve to allow the operation of nuclear power plants at an even higher level of optimization, maximum safety in line with the state of the art, and demonstrably competitive electricity generating costs. (orig.) [German] Oberstes Ziel des Betriebs von Kernkraftwerken wird auch in Zukunft uneingeschraenkt deren Sicherheit sein, bei gleichzeitiger Beruecksichtigung der durch die Liberalisierung des Strommarktes bedeutungsvoller gewordenen wirtschaftlichen Komponente. Bislang wurden die Erzeugungskosten in Kernkraftwerken durch Erhoehung der Stromerzeugungsleistung und durch hohe Zeit- und Arbeitsverfuegbarkeiten optimiert. Auf Grund der erreichten

  15. A Novel Approach for Risk Minimization in Life-Cycle Oil Production Optimization

    Capolei, Andrea; Christiansen, Lasse Hjuler; Jørgensen, John Bagterp

    2017-01-01

    The oil research community has invested much effort into computer aided optimization to enhance oil recovery. While simulation studies have demonstrated the potential of model-based technology to improve industrial standards, the largely unknown geology of subsurface reservoirs limits applications...... to commercial oil fields. In particular, uncertain model descriptions lead to risks of profit loss. To address the challenges of geological uncertainty, this paper proposes offset risk minimization. As opposed to existing methodologies of the oil literature, the offset approach minimizes risk of profit loss...

  16. Optimization of the scheduled maintenance on the power units of the nuclear power plants with WWER

    Skalozubov, V.I.; Kovrizhkin, Yu.L.; Kolykhanov, V.N.; Kochneva, V.Yu.; Urbanskij, V.V.

    2008-01-01

    The advanced international and domestic experience in the field of the maintenance optimization of the power units of NPPs, as well, as on the base of the planning optimization, the maintenance organization and carrying out, the technical maintenance and repair control system automatization, the testing and monitoring optimization during the service process, the modernization of the technology and technical tools of the maintenance service and control is represented

  17. Risk-Informed Decisions Optimization in Inspection and Maintenance

    Robertas Alzbutas

    2002-01-01

    The Risk-Informed Approach (RIA) used to support decisions related to inspection and maintenance program is considered. The use of risk-informed methods can help focus the adequate in-service inspections and control on the more important locations of complex dynamic systems. The focus is set on the highest risk measured as conditional core damage frequency, which is produced by the frequencies of degradation and final failure at different locations combined with the conditional failure consequence probability. The probabilities of different degradation states per year and consequences are estimated quantitatively. The investigation of inspection and maintenance process is presented as the combination of deterministic and probabilistic analysis based on general risk-informed model, which includes the inspection and maintenance program features. Such RIA allows an optimization of inspection program while maintaining probabilistic and fundamental deterministic safety requirements. The failure statistics analysis is used as well as the evaluation of reliability of inspections. The assumptions regarding the effectiveness of the inspection methods are based on a classification of the accessibility of the welds during the inspection and on the different techniques used for inspection. The probability of defect detection is assumed to depend on the parameters either through logarithmic or logit transformation. As example the modeling of the pipe systems inspection process is analyzed. The means to reduce a number of inspection sites and the cumulative radiation exposure to the NPP inspection personnel with a reduction of overall risk is presented together with used and developed software. The developed software can perform and administrate all the risk evaluations and ensure the possibilities to compare different options and perform sensitivity analysis. The approaches to define an acceptable level of risk are discussed. These approaches with appropriate software in

  18. Life-cycle evaluation of nitrogen-use in rice-farming systems: implications for economically-optimal nitrogen rates

    Y. Xia

    2011-11-01

    Full Text Available Nitrogen (N fertilizer plays an important role in agricultural systems in terms of food yield. However, N application rates (NARs are often overestimated over the rice (Oryza sativa L. growing season in the Taihu Lake region of China. This is largely because negative externalities are not entirely included when evaluating economically-optimal nitrogen rate (EONR, such as only individual N losses are taken into account, or the inventory flows of reactive N have been limited solely to the farming process when evaluating environmental and economic effects of N fertilizer. This study integrates important material and energy flows resulting from N use into a rice agricultural inventory that constitutes the hub of the life-cycle assessment (LCA method. An economic evaluation is used to determine an environmental and economic NAR for the Taihu Lake region. The analysis reveals that production and exploitation processes consume the largest proportion of resources, accounting for 77.2 % and 22.3 % of total resources, respectively. Regarding environmental impact, global warming creates the highest cost with contributions stemming mostly from fertilizer production and farming processes. Farming process incurs the biggest environmental impact of the three environmental impact categories considered, whereas transportation has a much smaller effect. When taking account of resource consumption and environmental cost, the marginal benefit of 1 kg rice would decrease from 2.4 to only 1.05 yuan. Accordingly, our current EONR has been evaluated at 187 kg N ha−1 for a single rice-growing season. This could enhance profitability, as well as reduce the N losses associated with rice growing.

  19. Advanced steam power plant concepts with optimized life-cycle costs: A new approach for maximum customer benefit

    Seiter, C.

    1998-07-01

    The use of coal power generation applications is currently enjoying a renaissance. New highly efficient and cost-effective plant concepts together with environmental protection technologies are the main factors in this development. In addition, coal is available on the world market at attractive prices and in many places it is more readily available than gas. At the economical leading edge, standard power plant concepts have been developed to meet the requirements of emerging power markets. These concepts incorporate the high technological state-of-the-art and are designed to achieve lowest life-cycle costs. Low capital cost, fuel costs and operating costs in combination with shortest lead times are the main assets that make these plants attractive especially for IPPs and Developers. Other aspects of these comprehensive concepts include turnkey construction and the willingness to participate in BOO/BOT projects. One of the various examples of such a concept, the 2 x 610-MW Paiton Private Power Project Phase II in Indonesia, is described in this paper. At the technological leading edge, Siemens has always made a major contribution and was pacemaker for new developments in steam power plant technology. Modern coal-fired steam power plants use computer-optimized process and plant design as well as advanced materials, and achieve efficiencies exceeding 45%. One excellent example of this high technology is the world's largest lignite-fired steam power plant Schwarze Pumpe in Germany, which is equipped with two 800 MW Siemens steam turbine generators with supercritical steam parameters. The world's largest 50-Hz single-shaft turbine generator with supercritical steam parameters rated at 1025 MW for the Niederaussem lignite-fired steam power plant in Germany is a further example of the sophisticated Siemens steam turbine technology and sets a new benchmark in this field.

  20. On the use of genetic algorithm to optimize industrial assets lifecycle management under safety and budget constraints

    Lonchampt, J.; Fessart, K. [EDF R and D, Departement MRI, 6, quai Watier, 78401 Chatou cedex (France)

    2013-07-01

    The purpose of this paper is to describe the method and tool dedicated to optimize investments planning for industrial assets. These investments may either be preventive maintenance tasks, asset enhancements or logistic investments such as spare parts purchases. The two methodological points to investigate in such an issue are: 1. The measure of the profitability of a portfolio of investments 2. The selection and planning of an optimal set of investments 3. The measure of the risk of a portfolio of investments The measure of the profitability of a set of investments in the IPOP tool is synthesised in the Net Present Value indicator. The NPV is the sum of the differences of discounted cash flows (direct costs, forced outages...) between the situations with and without a given investment. These cash flows are calculated through a pseudo-Markov reliability model representing independently the components of the industrial asset and the spare parts inventories. The component model has been widely discussed over the years but the spare part model is a new one based on some approximations that will be discussed. This model, referred as the NPV function, takes for input an investments portfolio and gives its NPV. The second issue is to optimize the NPV. If all investments were independent, this optimization would be an easy calculation, unfortunately there are two sources of dependency. The first one is introduced by the spare part model, as if components are indeed independent in their reliability model, the fact that several components use the same inventory induces a dependency. The second dependency comes from economic, technical or logistic constraints, such as a global maintenance budget limit or a safety requirement limiting the residual risk of failure of a component or group of component, making the aggregation of individual optimum not necessary feasible. The algorithm used to solve such a difficult optimization problem is a genetic algorithm. After a description

  1. On the use of genetic algorithm to optimize industrial assets lifecycle management under safety and budget constraints

    Lonchampt, J.; Fessart, K.

    2013-01-01

    The purpose of this paper is to describe the method and tool dedicated to optimize investments planning for industrial assets. These investments may either be preventive maintenance tasks, asset enhancements or logistic investments such as spare parts purchases. The two methodological points to investigate in such an issue are: 1. The measure of the profitability of a portfolio of investments 2. The selection and planning of an optimal set of investments 3. The measure of the risk of a portfolio of investments The measure of the profitability of a set of investments in the IPOP tool is synthesised in the Net Present Value indicator. The NPV is the sum of the differences of discounted cash flows (direct costs, forced outages...) between the situations with and without a given investment. These cash flows are calculated through a pseudo-Markov reliability model representing independently the components of the industrial asset and the spare parts inventories. The component model has been widely discussed over the years but the spare part model is a new one based on some approximations that will be discussed. This model, referred as the NPV function, takes for input an investments portfolio and gives its NPV. The second issue is to optimize the NPV. If all investments were independent, this optimization would be an easy calculation, unfortunately there are two sources of dependency. The first one is introduced by the spare part model, as if components are indeed independent in their reliability model, the fact that several components use the same inventory induces a dependency. The second dependency comes from economic, technical or logistic constraints, such as a global maintenance budget limit or a safety requirement limiting the residual risk of failure of a component or group of component, making the aggregation of individual optimum not necessary feasible. The algorithm used to solve such a difficult optimization problem is a genetic algorithm. After a description

  2. Optimum Maintenance Strategies for Highway Bridges

    Frangopol, Dan M.; Thoft-Christensen, Palle; Das, Parag C.

    As bridges become older and maintenance costs become higher, transportation agencies are facing challenges related to implementation of optimal bridge management programs based on life cycle cost considerations. A reliability-based approach is necessary to find optimal solutions based on minimum...... expected life-cycle costs or maximum life-cycle benefits. This is because many maintenance activities can be associated with significant costs, but their effects on bridge safety can be minor. In this paper, the program of an investigation on optimum maintenance strategies for different bridge types...... is described. The end result of this investigation will be a general reliability-based framework to be used by the UK Highways Agency in order to plan optimal strategies for the maintenance of its bridge network so as to optimize whole-life costs....

  3. Preventive maintenance: optimization of time - based discard decisions at the bruce nuclear generating station

    Doyle, E.K.; Jardine, A.K.S.

    2001-01-01

    The use of various maintenance optimization techniques at Bruce has lead to cost effective preventive maintenance applications for complex systems. As previously reported at ICONE 6 in New Orleans, 1996, several innovative practices reduced Reliability Centered Maintenance costs while maintaining the accuracy of the analysis. The optimization strategy has undergone further evolution and at the present an Integrated Maintenance Program (IMP) is in place where an Expert Panel consisting of all players/experts proceed through each system in a disciplined fashion and reach agreement on all items under a rigorous time frame. It is well known that there are essentially 3 maintenance based actions that can flow from a Maintenance Optimization Analysis: condition based maintenance, time based maintenance and time based discard. The present effort deals with time based discard decisions. Maintenance data from the Remote On-Power Fuel Changing System was used. (author)

  4. Optimizing Maintenance Planning in the Production Industry Using the Markovian Approach

    B Kareem

    2012-12-01

    Full Text Available Maintenance is an essential activity in every manufacturing establishment, as manufacturing effectiveness counts on the functionality of production equipment and machinery in terms of their productivity and operational life. Maintenance cost minimization can be achieved by adopting an appropriate maintenance planning policy. This paper applies the Markovian approach to maintenance planning decision, thereby generating optimal maintenance policy from the identified alternatives over a specified period of time. Markov chains, transition matrices, decision processes, and dynamic programming models were formulated for the decision problem related to maintenance operations of a cable production company. Preventive and corrective maintenance data based on workloads and costs, were collected from the company and utilized in this study. The result showed variability in the choice of optimal maintenance policy that was adopted in the case study. Post optimality analysis of the process buttressed the claim. The proposed approach is promising for solving the maintenance scheduling decision problems of the company.

  5. Risk-Based Operation and Maintenance of Offshore Wind Turbines

    Nielsen, Jannie Jessen; Sørensen, John Dalsgaard

    2009-01-01

    For offshore wind turbines costs to operation and maintenance are substantial. This paper describes a risk-based lifecycle approach for optimal planning of operation and maintenance. The approach is based on pre-posterior Bayesian decision theory. Deterioration mechanisms such as fatigue, corrosion...

  6. RCM optimization of a system under both preventive and corrective maintenance

    Bris, R.; Cepin, M.

    2005-01-01

    Testing and maintenance activities of power electrical equipment are an important potential for both risk and cost reduction. A multi-objective maintenance optimization method is presented based on the Genetic Algorithms (GA) technique. The method determines the optimal schedule of preventive maintenance actions based on minimization both selected risk measure and cost. Applied cost model takes into account both preventive and corrective maintenance. This paper also presents application of the methodology to optimize maintenance of a real distribution network 22 kV. Conclusions and recommendations for practice are made on the basis of obtained results. (author)

  7. Optimization of reliability centered predictive maintenance scheme for inertial navigation system

    Jiang, Xiuhong; Duan, Fuhai; Tian, Heng; Wei, Xuedong

    2015-01-01

    The goal of this study is to propose a reliability centered predictive maintenance scheme for a complex structure Inertial Navigation System (INS) with several redundant components. GO Methodology is applied to build the INS reliability analysis model—GO chart. Components Remaining Useful Life (RUL) and system reliability are updated dynamically based on the combination of components lifetime distribution function, stress samples, and the system GO chart. Considering the redundant design in INS, maintenance time is based not only on components RUL, but also (and mainly) on the timing of when system reliability fails to meet the set threshold. The definition of components maintenance priority balances three factors: components importance to system, risk degree, and detection difficulty. Maintenance Priority Number (MPN) is introduced, which may provide quantitative maintenance priority results for all components. A maintenance unit time cost model is built based on components MPN, components RUL predictive model and maintenance intervals for the optimization of maintenance scope. The proposed scheme can be applied to serve as the reference for INS maintenance. Finally, three numerical examples prove the proposed predictive maintenance scheme is feasible and effective. - Highlights: • A dynamic PdM with a rolling horizon is proposed for INS with redundant components. • GO Methodology is applied to build the system reliability analysis model. • A concept of MPN is proposed to quantify the maintenance sequence of components. • An optimization model is built to select the optimal group of maintenance components. • The optimization goal is minimizing the cost of maintaining system reliability

  8. Life-cycle cost as basis to optimize waste collection in space and time: A methodology for obtaining a detailed cost breakdown structure.

    Sousa, Vitor; Dias-Ferreira, Celia; Vaz, João M; Meireles, Inês

    2018-05-01

    Extensive research has been carried out on waste collection costs mainly to differentiate costs of distinct waste streams and spatial optimization of waste collection services (e.g. routes, number, and location of waste facilities). However, waste collection managers also face the challenge of optimizing assets in time, for instance deciding when to replace and how to maintain, or which technological solution to adopt. These issues require a more detailed knowledge about the waste collection services' cost breakdown structure. The present research adjusts the methodology for buildings' life-cycle cost (LCC) analysis, detailed in the ISO 15686-5:2008, to the waste collection assets. The proposed methodology is then applied to the waste collection assets owned and operated by a real municipality in Portugal (Cascais Ambiente - EMAC). The goal is to highlight the potential of the LCC tool in providing a baseline for time optimization of the waste collection service and assets, namely assisting on decisions regarding equipment operation and replacement.

  9. Systematic maintenance analysis with decision support method and tool for optimizing maintenance programme

    Laakso, K.; Simola, K.; Dorrepaal, J.; Skogberg, P.

    1999-01-01

    This report describes an approach to evaluate the effectiveness of test and maintenance programs of technical systems used during several years. The method combines an analysis of the historical data on faults and repairs with an analysis of the history of periodic testing and preventive maintenance action programs. The application of the maintenance analysis from the methodological point of view in the reliability centered maintenance (RCM) project for Barsebaeck nuclear power plant is described. In order to limit the analysis resources, a method for ranking of objects for maintenance analysis is needed. Preliminary suggestions for changes in maintenance action programs are based on signals from simple maintenance indicators and qualitative analysis of underlying data on failures and maintenance. To facilitate generation of maintenance indicators, and make the maintenance analysis more efficient, a powerful and suitable data treatment tool is needed for analysis of the work order history. In the final maintenance decisions, additional decision criteria must be taken into account, and thus a more formal decision analysis is often needed for decision support. (au)

  10. Analytical method for optimization of maintenance policy based on available system failure data

    Coria, V.H.; Maximov, S.; Rivas-Dávalos, F.; Melchor, C.L.; Guardado, J.L.

    2015-01-01

    An analytical optimization method for preventive maintenance (PM) policy with minimal repair at failure, periodic maintenance, and replacement is proposed for systems with historical failure time data influenced by a current PM policy. The method includes a new imperfect PM model based on Weibull distribution and incorporates the current maintenance interval T 0 and the optimal maintenance interval T to be found. The Weibull parameters are analytically estimated using maximum likelihood estimation. Based on this model, the optimal number of PM and the optimal maintenance interval for minimizing the expected cost over an infinite time horizon are also analytically determined. A number of examples are presented involving different failure time data and current maintenance intervals to analyze how the proposed analytical optimization method for periodic PM policy performances in response to changes in the distribution of the failure data and the current maintenance interval. - Highlights: • An analytical optimization method for preventive maintenance (PM) policy is proposed. • A new imperfect PM model is developed. • The Weibull parameters are analytically estimated using maximum likelihood. • The optimal maintenance interval and number of PM are also analytically determined. • The model is validated by several numerical examples

  11. Monitoring Strategies in Permeable Pavement Systems to Optimize Maintenance Scheduling

    As the surface in a permeable pavement system clogs and performance decreases, maintenance is required to preserve the design function. Currently, guidance is limited for scheduling maintenance on an as needed basis. Previous research has shown that surface clogging in a permea...

  12. Optimizing preventive maintenance policy: A data-driven application for a light rail braking system.

    Corman, Francesco; Kraijema, Sander; Godjevac, Milinko; Lodewijks, Gabriel

    2017-10-01

    This article presents a case study determining the optimal preventive maintenance policy for a light rail rolling stock system in terms of reliability, availability, and maintenance costs. The maintenance policy defines one of the three predefined preventive maintenance actions at fixed time-based intervals for each of the subsystems of the braking system. Based on work, maintenance, and failure data, we model the reliability degradation of the system and its subsystems under the current maintenance policy by a Weibull distribution. We then analytically determine the relation between reliability, availability, and maintenance costs. We validate the model against recorded reliability and availability and get further insights by a dedicated sensitivity analysis. The model is then used in a sequential optimization framework determining preventive maintenance intervals to improve on the key performance indicators. We show the potential of data-driven modelling to determine optimal maintenance policy: same system availability and reliability can be achieved with 30% maintenance cost reduction, by prolonging the intervals and re-grouping maintenance actions.

  13. Optimization of maintenance policy using the proportional hazard model

    Samrout, M. [Information Sciences and Technologies Institute, University of Technology of Troyes, 10000 Troyes (France)], E-mail: mohamad.el_samrout@utt.fr; Chatelet, E. [Information Sciences and Technologies Institute, University of Technology of Troyes, 10000 Troyes (France)], E-mail: chatelt@utt.fr; Kouta, R. [M3M Laboratory, University of Technology of Belfort Montbeliard (France); Chebbo, N. [Industrial Systems Laboratory, IUT, Lebanese University (Lebanon)

    2009-01-15

    The evolution of system reliability depends on its structure as well as on the evolution of its components reliability. The latter is a function of component age during a system's operating life. Component aging is strongly affected by maintenance activities performed on the system. In this work, we consider two categories of maintenance activities: corrective maintenance (CM) and preventive maintenance (PM). Maintenance actions are characterized by their ability to reduce this age. PM consists of actions applied on components while they are operating, whereas CM actions occur when the component breaks down. In this paper, we expound a new method to integrate the effect of CM while planning for the PM policy. The proportional hazard function was used as a modeling tool for that purpose. Interesting results were obtained when comparison between policies that take into consideration the CM effect and those that do not is established.

  14. Optimization of series-parallel multi-state systems under maintenance policies

    Nourelfath, Mustapha; Ait-Kadi, Daoud

    2007-01-01

    In the redundancy optimization problem, the design goal is achieved by discrete choices made from components available in the market. In this paper, the problem is to find, under reliability constraints, the minimal cost configuration of a multi-state series-parallel system, which is subject to a specified maintenance policy. The number of maintenance teams is less than the number of repairable components, and a maintenance policy specifies the priorities between the system components. To take into account the dependencies resulting from the sharing of maintenance teams, the universal generating function approach is coupled with a Markov model. The resulting optimization approach has the advantage of being mainly analytical

  15. The Bayesian statistical decision theory applied to the optimization of generating set maintenance

    Procaccia, H.; Cordier, R.; Muller, S.

    1994-11-01

    The difficulty in RCM methodology is the allocation of a new periodicity of preventive maintenance on one equipment when a critical failure has been identified: until now this new allocation has been based on the engineer's judgment, and one must wait for a full cycle of feedback experience before to validate it. Statistical decision theory could be a more rational alternative for the optimization of preventive maintenance periodicity. This methodology has been applied to inspection and maintenance optimization of cylinders of diesel generator engines of 900 MW nuclear plants, and has shown that previous preventive maintenance periodicity can be extended. (authors). 8 refs., 5 figs

  16. RCM [reliability-centered maintenance] at Ginna: Preventive maintenance program optimization at year 20

    Edgar, E.C.

    1989-01-01

    The reliability-centered maintenance (RCM) program at Rochester Gas ampersand Electric Company's Ginna station is entering its second year. Of the 20 systems originally selected for evaluation, 10 are in various stages of completion, and recommendations resulting from the earliest systems studied are now being implemented. As expected, few major discoveries have been made in terms of preventive maintenance program failings or excesses. The performance of the now 20-yr-old plant has been excellent in recent years, and objectives focus more on ensuring continued high standards of safety, reliability, and economy than on maintenance program cost reduction

  17. Optimal infrastructure maintenance scheduling problem under budget uncertainty.

    2010-05-01

    This research addresses a general class of infrastructure asset management problems. Infrastructure : agencies usually face budget uncertainties that will eventually lead to suboptimal planning if : maintenance decisions are made without taking the u...

  18. Optimal Maintenance Crew Composition and Enhancement of Crew Productivity

    2008-08-01

    The South Carolina Department of Transportation dedicates a large portion of both : its budget and other resources to the maintenance of the States transportation : infrastructure. In order to maximize the efficiency and productivity of the State...

  19. Reliability centered maintenance : a case study of railway transit maintenance to achieve optimal performance.

    2010-12-01

    The purpose of this qualitative case study was to identify the types of obstacles and patterns experienced by a single heavy rail transit agency located in North America that embedded a Reliability Centered Maintenance (RCM) Process. The outcome of t...

  20. Application of reliability centred maintenance to optimize operation and maintenance in nuclear power plants

    2007-05-01

    In order to increase Member States capabilities in utilizing good engineering and management practices the Agency has developed a series of Technical Documents (TECDOCs) to describe best practices and members experience in the application of them. This TECDOC describes the concept of Reliability Centred Maintenance (RCM) which is the term used to describe a systematic approach to the evaluation, design and development of cost effective maintenance programmes for plant and equipment. The concept has been in existence for over 25 years originating in the civil aviation sector. This TECDOC supplements previous IAEA publications on the subject and seeks to reflect members experience in the application of the principles involved. The process focuses on the functionality of the plant and equipment and the critical failure mechanisms that could result in the loss of functionality. When employed effectively the process can result in the elimination of unnecessary maintenance activities and the identification and introduction of measures to address deficiencies in the maintenance programme. Overall the process can result in higher levels of reliability for the plant and equipment at reduced cost and demands on finite maintenance resources. The application of the process requires interaction between the operators and the maintenance practitioners which is often lacking in traditional maintenance programmes. The imposition of this discipline produces the added benefit of improved information flows between the key players in plant and equipment management with the result that maintenance activities and operational practices are better informed. This publication was produced within IAEA programme on nuclear power plants operating performance and life cycle management

  1. A methodology based in particle swarm optimization algorithm for preventive maintenance focused in reliability and cost

    Luz, Andre Ferreira da

    2009-01-01

    In this work, a Particle Swarm Optimization Algorithm (PSO) is developed for preventive maintenance optimization. The proposed methodology, which allows the use flexible intervals between maintenance interventions, instead of considering fixed periods (as usual), allows a better adaptation of scheduling in order to deal with the failure rates of components under aging. Moreover, because of this flexibility, the planning of preventive maintenance becomes a difficult task. Motivated by the fact that the PSO has proved to be very competitive compared to other optimization tools, this work investigates the use of PSO as an alternative tool of optimization. Considering that PSO works in a real and continuous space, it is a challenge to use it for discrete optimization, in which scheduling may comprise variable number of maintenance interventions. The PSO model developed in this work overcome such difficulty. The proposed PSO searches for the best policy for maintaining and considers several aspects, such as: probability of needing repair (corrective maintenance), the cost of such repairs, typical outage times, costs of preventive maintenance, the impact of maintaining the reliability of systems as a whole, and the probability of imperfect maintenance. To evaluate the proposed methodology, we investigate an electro-mechanical system consisting of three pumps and four valves, High Pressure Injection System (HPIS) of a PWR. Results show that PSO is quite efficient in finding the optimum preventive maintenance policies for the HPIS. (author)

  2. Application of Dr. Mainte, integrated simulator of maintenance optimization, to LWRs

    Isobe, Yoshihiro; Sagisaka, Mitsuyuki; Etoh, Junji; Matsunaga, Takashi; Kosaka, Toru; Matsumoto, Satoshi; Yoshimura, Shinobu

    2015-01-01

    Dr. Mainte, an integrated simulator for maintenance optimization of LWRs (Light Water Reactors) is based on PFM (Probabilistic Fracture Mechanics) analyses. The concept of the simulator is to provide a decision-making system to optimize maintenance activities for typical components and piping systems in nuclear power plants totally and quantitatively in terms of safety, availability, economic rationality, environmental impact and social acceptance. For the further improvement of the safety and availability of nuclear power plants, the effect of human error and its reduction on the optimization of maintenance activities have been studied. In addition, an approach of reducing human error is proposed. (author)

  3. Optimization of maintenance strategies in case of data uncertainties; Optimierung von Instandhaltungsstrategien bei unscharfen Eingangsdaten

    Aha, Ulrich

    2013-07-01

    Maintenance strategies are aimed to keep a technical facility functioning in spite of damaging processes (wear, corrosion, fatigue) with simultaneous control of these processes. The project optimization of maintenance strategies in case of data uncertainties is aimed to optimize maintenance measures like preventive measures (lubrication etc.), inspections and replacements to keep the facility/plant operating including the minimization of financial costs. The report covers the following topics: modeling assumptions, model development and optimization procedure, results for a conventional power plant and an oxyfuel plant.

  4. Optimization of maintenance programme at Daya Bay Nuclear Power Station based on RCM analysis results

    Liu Min

    2003-01-01

    This paper begins with an introduction to Guangdong Daya Bay Nuclear Power Station (GNPS) and gives a simple introduction to the operations and maintenance documentation system at GNPS. It then will review the maintenance program guidelines base and the associated problems prior to the application of reliability centered maintenance (RCM). How RCM was implemented at GNPS, how the results of RCM analysis were used to optimize the maintenance program and test program, and what is the interface between RCM and the existing maintenance program will be shown. Next, it will show the successful implementation of RCM at GNPS resulted in the following changes: A new understanding of equipment failure challenges operations and maintenance beliefs, maintenance concepts undergo a large change, maintenance program and periodic testing program are continuously modified and optimized, new on-condition maintenance technologies are introduced, non-productive scheduled overhauls are discarded, maintenance costs are effectively controlled, maintenance appropriateness has improved, management of hidden failures is more effective and timely. It will show the benefit of greater equipment reliability brought about by all of these changes, which in turn increases the reliability and safety of the entire power station. (author)

  5. Preventive maintenance optimization for a stochastically degrading system with a random initial age

    Sidibe, I.B.; Khatab, A.; Diallo, C.; Kassambara, A.

    2017-01-01

    This paper investigates the optimal age replacement policy for used systems, such as second-hand products, which start their second life-cycle in a more severe environment with an initial age that is uncertain. This uncertain age is modelled as a random variable following continuous probability distributions. A mathematical model is developed to minimize the total expected cost per unit of time for these systems on an infinite time horizon. Optimality and existence conditions for a unique optimal solution are derived and used in a numerical procedure to solve the problem. Numerical experiments are provided to demonstrate the added value and the impacts of the random initial age on the optimal replacement policy.

  6. Optimal policies for cumulative damage models with maintenance last and first

    Zhao, Xufeng; Qian, Cunhua; Nakagawa, Toshio

    2013-01-01

    From the economical viewpoint of several combined PM policies in reliability theory, this paper takes up a standard cumulative damage model in which the notion of maintenance last is applied, i.e., the unit undergoes preventive maintenances before failure at a planned time T, at a damage level Z, or at a shock number N, whichever occurs last. Expected cost rates are detailedly formulated, and optimal problems of two alternative policies which combine time-based with condition-based preventive maintenances are discussed, i.e., optimal T L ⁎ for N, Z L ⁎ for T, and N L ⁎ for T are rigorously obtained. Comparison methods between such maintenance last and conventional maintenance first are explored. It is determined theoretically and numerically which policy should be adopted, according to the different methods in different cases when the time-based or the condition-based PM policy is optimized.

  7. Spare parts sharing with joint optimization of maintenance and inventory policies

    Larsen, Christian; Wong, Hartanto Wijaya; Nielsen, Lars Relund

    We consider a collaborative arrangement where a number of companies are willing to share expensive spare parts, required for both failure replacement and preventive maintenance purposes. We develop a discrete-time Markov decision model for the joint optimization of maintenance and spare parts...

  8. Investigating the Optimal Management Strategy for a Healthcare Facility Maintenance Program

    Gaillard, Daria

    2004-01-01

    ...: strategic partnering with an equipment management firm. The objective of this study is to create a decision-model for selecting the optimal management strategy for a healthcare organization's facility maintenance program...

  9. Global optimization of maintenance and surveillance testing based on reliability and probabilistic safety assessment. Research project

    Martorell, S.; Serradell, V.; Munoz, A.; Sanchez, A.

    1997-01-01

    Background, objective, scope, detailed working plan and follow-up and final product of the project ''Global optimization of maintenance and surveillance testing based on reliability and probabilistic safety assessment'' are described

  10. Maintenance optimization under non-constant probabilities of imperfect inspections

    Driessen, J.P.C.; Peng, H.; van Houtum, G.J.J.A.N.

    2017-01-01

    In this research, we study a single-component system that is characterized by three distinct deterioration states, cf. the Delay Time Model: normal, defective, and failed. The system is inspected periodically, and preventive system maintenance is done after a given number of inspections. The

  11. Extended great deluge algorithm for the imperfect preventive maintenance optimization of multi-state systems

    Nahas, Nabil; Khatab, Abdelhakim; Ait-Kadi, Daoud; Nourelfath, Mustapha

    2008-01-01

    This paper deals with preventive maintenance optimization problem for multi-state systems (MSS). This problem was initially addressed and solved by Levitin and Lisnianski [Optimization of imperfect preventive maintenance for multi-state systems. Reliab Eng Syst Saf 2000;67:193-203]. It consists on finding an optimal sequence of maintenance actions which minimizes maintenance cost while providing the desired system reliability level. This paper proposes an approach which improves the results obtained by genetic algorithm (GENITOR) in Levitin and Lisnianski [Optimization of imperfect preventive maintenance for multi-state systems. Reliab Eng Syst Saf 2000;67:193-203]. The considered MSS have a range of performance levels and their reliability is defined to be the ability to meet a given demand. This reliability is evaluated by using the universal generating function technique. An optimization method based on the extended great deluge algorithm is proposed. This method has the advantage over other methods to be simple and requires less effort for its implementation. The developed algorithm is compared to than in Levitin and Lisnianski [Optimization of imperfect preventive maintenance for multi-state systems. Reliab Eng Syst Saf 2000;67:193-203] by using a reference example and two newly generated examples. This comparison shows that the extended great deluge gives the best solutions (i.e. those with minimal costs) for 8 instances among 10

  12. The Report of Maintenance and Management Optimization for the Korean Fossil Power Plants

    Ha, J.S.; Yoo, K.B.; Chung, H.; Chang, S.H. [Korea Electric Power Research Institute, Taejon (Korea)

    2002-07-01

    For the Korean fossil power plants, the main component and facillities were classified by maintainability, reliability, production, cost model to assess the cost effective performance of a power plant's maintenance. Maintenance program interacts with the generation process and estimates the leverage provided by expenditures on preventive maintenance. This optimization method is an engineering tool for tracking each asset's production and cost performance under appropriate engineering approximations. Thus, it provides useful insights into where maintenance resources can be expended most effectively to increase generation and reduce operating costs. (author). 7 refs., 3 tabs.

  13. Application of genetic algorithms to the maintenance scheduling optimization in a nuclear system basing on reliability

    Lapa, Celso M. Franklin; Pereira, Claudio M.N.A.; Mol, Antonio C. de Abreu

    1999-01-01

    This paper presents a solution based on genetic algorithm and probabilistic safety analysis that can be applied in the optimization of the preventive maintenance politic of nuclear power plant safety systems. The goal of this approach is to improve the average availability of the system through the optimization of the preventive maintenance scheduling politic. The auxiliary feed water system of a two loops pressurized water reactor is used as a sample case, in order to demonstrate the effectiveness of the proposed method. The results, when compared to those obtained by some standard maintenance politics, reveal quantitative gains and operational safety levels. (author)

  14. A survey of research projects in maintenance optimization for Electricite de France power plants

    Jacquot, J.P.

    1996-01-01

    Six years ago, Electricite de France launched a Reliability Centered Maintenance (RCM) pilot project to optimize preventive maintenance for its nuclear power plants. After a feasibility study, a Reliability Centered Maintenance (RCM) method was standardized. It is now applied on a large scale to the 50 EDF nuclear units. A RCM workstation based on this standardized method has been developed and is now used in each plant. In the next step, the author will consider whether a risk based approach can be included in this RCM process in order to analyze critical passive components such as pipes and supports. Considering the potential advantages of these optimization techniques, a dedicated process has been also developed for maintenance of future plants, gas turbines, or nuclear units. For these future plants, a Logistic Support Analysis (LSA) will be added to the RCM process to globally evaluate availability, safety and maintenance costs. This paper will present a survey of these different developments of methods and tools

  15. An optimal dynamic interval preventive maintenance scheduling for series systems

    Gao, Yicong; Feng, Yixiong; Zhang, Zixian; Tan, Jianrong

    2015-01-01

    This paper studies preventive maintenance (PM) with dynamic interval for a multi-component system. Instead of equal interval, the time of PM period in the proposed dynamic interval model is not a fixed constant, which varies from interval-down to interval-up. It is helpful to reduce the outage loss on frequent repair parts and avoid lack of maintenance of the equipment by controlling the equipment maintenance frequency, when compared to a periodic PM scheme. According to the definition of dynamic interval, the reliability of system is analyzed from the failure mechanisms of its components and the different effects of non-periodic PM actions on the reliability of the components. Following the proposed model of reliability, a novel framework for solving the non-periodical PM schedule with dynamic interval based on the multi-objective genetic algorithm is proposed. The framework denotes the strategies include updating strategy, deleting strategy, inserting strategy and moving strategy, which is set to correct the invalid population individuals of the algorithm. The values of the dynamic interval and the selections of PM action for the components on every PM stage are determined by achieving a certain level of system availability with the minimum total PM-related cost. Finally, a typical rotary table system of NC machine tool is used as an example to describe the proposed method. - Highlights: • A non-periodic preventive maintenance scheduling model is proposed. • A framework for solving the non-periodical PM schedule problem is developed. • The interval of non-periodic PM is flexible and schedule can be better adjusted. • Dynamic interval leads to more efficient solutions than fixed interval does

  16. Development of an evaluation method for optimization of maintenance strategy in commercial plant

    Ito, Satoshi; Shiraishi, Natsuki; Yuki, Kazuhisa; Hashizume, Hidetoshi

    2006-01-01

    In this study, a new simulation method is developed for optimization of maintenance strategy in NPP as a multiple-objective optimization problem (MOP). The result of operation is evaluated as the average of the following three measures in 3,000 trials: Cost of Electricity (COE) as economic risk, Frequency of unplanned shutdown as plant reliability, and Unavailability of Regular Service System (RSS) and Engineering Safety Features (ESF) as safety measures. The following maintenance parameters are considered to evaluate several risk in plant operation by changing maintenance strategy: planned outage cycle, surveillance cycle, major inspection cycle, and surveillance cycle depending on the value of Fussel-Vesely importance measure. By using the Decision-Making method based on AHP, there are individual tendencies depending on individual decision-maker. Therefore this study could be useful for resolving the problem of maintenance optimization as a MOP. (author)

  17. Cloud Computing Governance Lifecycle

    Soňa Karkošková

    2016-06-01

    Full Text Available Externally provisioned cloud services enable flexible and on-demand sourcing of IT resources. Cloud computing introduces new challenges such as need of business process redefinition, establishment of specialized governance and management, organizational structures and relationships with external providers and managing new types of risk arising from dependency on external providers. There is a general consensus that cloud computing in addition to challenges brings many benefits but it is unclear how to achieve them. Cloud computing governance helps to create business value through obtain benefits from use of cloud computing services while optimizing investment and risk. Challenge, which organizations are facing in relation to governing of cloud services, is how to design and implement cloud computing governance to gain expected benefits. This paper aims to provide guidance on implementation activities of proposed Cloud computing governance lifecycle from cloud consumer perspective. Proposed model is based on SOA Governance Framework and consists of lifecycle for implementation and continuous improvement of cloud computing governance model.

  18. Joint optimization of preventive maintenance and spare parts inventory for an optimal production plan with consideration of CO_2 emission

    Ba, Kader; Dellagi, Sofiene; Rezg, Nidhal; Erray, Walid

    2016-01-01

    This article presents a joint optimization of spare parts inventory and preventive maintenance. While minimizing CO_2 emissions, this approach is based on an optimal production plan achieved thanks to the HMMS model. The process which is studied in this paper only manufactures one type of product. The purpose of the paper is to determine for a random demand over a given period, a cost-effective production plan and a maintenance policy which integrates a spare parts strategy in accordance with environmental requirements and regulations. Our green spare parts management can be defined as a set of actions that are applied in order to decrease the spare parts footprint in its lifetime (Ba et al., 2015) [1]. Indeed, we take into account the spare parts characteristics (new or used) which will be used during maintenance actions (preventive or corrective) to preserve the environment. Consequently, we set up analytical models based on the effect of the production rate on the system deterioration so as to substantially cut the maintenance costs, production costs and CO_2 emissions. To evaluate the performance of our models, we give some illustrative examples. - Highlights: • Establishment of an optimal production plan for a manufacturing process. • Cost-effective maintenance strategy with a green spare parts strategy. • Possibility to choose between used and new spare parts to execute maintenance action.

  19. Addressing imperfect maintenance modelling uncertainty in unavailability and cost based optimization

    Sanchez, Ana [Department of Statistics and Operational Research, Polytechnic University of Valencia, Camino de Vera, s/n, 46071 Valencia (Spain); Carlos, Sofia [Department of Chemical and Nuclear Engineering, Polytechnic University of Valencia, Camino de Vera, s/n, 46071 Valencia (Spain); Martorell, Sebastian [Department of Chemical and Nuclear Engineering, Polytechnic University of Valencia, Camino de Vera, s/n, 46071 Valencia (Spain)], E-mail: smartore@iqn.upv.es; Villanueva, Jose F. [Department of Chemical and Nuclear Engineering, Polytechnic University of Valencia, Camino de Vera, s/n, 46071 Valencia (Spain)

    2009-01-15

    Optimization of testing and maintenance activities performed in the different systems of a complex industrial plant is of great interest as the plant availability and economy strongly depend on the maintenance activities planned. Traditionally, two types of models, i.e. deterministic and probabilistic, have been considered to simulate the impact of testing and maintenance activities on equipment unavailability and the cost involved. Both models present uncertainties that are often categorized as either aleatory or epistemic uncertainties. The second group applies when there is limited knowledge on the proper model to represent a problem, and/or the values associated to the model parameters, so the results of the calculation performed with them incorporate uncertainty. This paper addresses the problem of testing and maintenance optimization based on unavailability and cost criteria and considering epistemic uncertainty in the imperfect maintenance modelling. It is framed as a multiple criteria decision making problem where unavailability and cost act as uncertain and conflicting decision criteria. A tolerance interval based approach is used to address uncertainty with regard to effectiveness parameter and imperfect maintenance model embedded within a multiple-objective genetic algorithm. A case of application for a stand-by safety related system of a nuclear power plant is presented. The results obtained in this application show the importance of considering uncertainties in the modelling of imperfect maintenance, as the optimal solutions found are associated with a large uncertainty that influences the final decision making depending on, for example, if the decision maker is risk averse or risk neutral.

  20. Addressing imperfect maintenance modelling uncertainty in unavailability and cost based optimization

    Sanchez, Ana; Carlos, Sofia; Martorell, Sebastian; Villanueva, Jose F.

    2009-01-01

    Optimization of testing and maintenance activities performed in the different systems of a complex industrial plant is of great interest as the plant availability and economy strongly depend on the maintenance activities planned. Traditionally, two types of models, i.e. deterministic and probabilistic, have been considered to simulate the impact of testing and maintenance activities on equipment unavailability and the cost involved. Both models present uncertainties that are often categorized as either aleatory or epistemic uncertainties. The second group applies when there is limited knowledge on the proper model to represent a problem, and/or the values associated to the model parameters, so the results of the calculation performed with them incorporate uncertainty. This paper addresses the problem of testing and maintenance optimization based on unavailability and cost criteria and considering epistemic uncertainty in the imperfect maintenance modelling. It is framed as a multiple criteria decision making problem where unavailability and cost act as uncertain and conflicting decision criteria. A tolerance interval based approach is used to address uncertainty with regard to effectiveness parameter and imperfect maintenance model embedded within a multiple-objective genetic algorithm. A case of application for a stand-by safety related system of a nuclear power plant is presented. The results obtained in this application show the importance of considering uncertainties in the modelling of imperfect maintenance, as the optimal solutions found are associated with a large uncertainty that influences the final decision making depending on, for example, if the decision maker is risk averse or risk neutral

  1. Maintenance optimization and prognostics of residual life - A state of the art report

    Nystad, Bent

    2006-01-15

    In many industries a huge part of the daily operational costs are related to maintenance. One key function in cutting costs is in optimization of the maintenance efforts. A major task is to change the work culture and work processes from being repair oriented, with focus on repairing breakdowns, to being proactive and maintain critical parts/systems before failures occur. Estimation of residual life distributions is of great need to obtain an optimum preventive maintenance strategy. In this report two approaches for estimation of residual life are discussed. The first model assumes that the residual life follows a Weibull distribution where the parameters are dependent on expert judgement, inspection data, repair data, and technical health trends. The second model is based on a continuous time Markov chain. In maintenance optimization a quantitative approach like the mean residual life estimation is needed in addition to a qualitative approach like the Reliability Centred Maintenance (RCM) methodology to give support for e.g. optimization of the maintenance overhaul intervals.The use of residual life knowledge in opportunistic maintenance is also discussed.(auth)

  2. Bus Lifecycle Cost Model for Federal Land Management Agencies.

    2011-09-30

    The Bus Lifecycle Cost Model is a spreadsheet-based planning tool that estimates capital, operating, and maintenance costs for various bus types over the full lifecycle of the vehicle. The model is based on a number of operating characteristics, incl...

  3. Joint Optimization of Preventive Maintenance and Spare Parts Inventory with Appointment Policy

    Jing Cai

    2017-01-01

    Full Text Available Under the background of the wide application of condition-based maintenance (CBM in maintenance practice, the joint optimization of maintenance and spare parts inventory is becoming a hot research to take full advantage of CBM and reduce the operational cost. In order to avoid both the high inventory level and the shortage of spare parts, an appointment policy of spare parts is first proposed based on the prediction of remaining useful lifetime, and then a corresponding joint optimization model of preventive maintenance and spare parts inventory is established. Due to the complexity of the model, the combination method of genetic algorithm and Monte Carlo is presented to get the optimal maximum inventory level, safety inventory level, potential failure threshold, and appointment threshold to minimize the cost rate. Finally, the proposed model is studied through a case study and compared with both the separate optimization and the joint optimization without appointment policy, and the results show that the proposed model is more effective. In addition, the sensitivity analysis shows that the proposed model is consistent with the actual situation of maintenance practices and inventory management.

  4. Optimized maintenance concept of safety relevant valves related to ageing management features in nuclear power plants

    Koring, R.

    2007-01-01

    This paper presents the existing concept in E.ON Kernkraft and its sound application to ageing management issues by focussing on group 2 components such as safety relevant valves. It is demonstrated how the maintenance concept of safety relevant valves is supported by a valve diagnostic system accompanied by an applied procedure to assess the measured results with respect to the required functionality and ageing phenomena. Furthermore this concept has been developed to optimize the existing preventive maintenance of the safety relevant valves by implementing condition oriented aspects derived from the diagnostic results. The main issue of this maintenance concept is to demonstrate the high level of the secured function, reliability and performance of the safety relevant valves within an integrated ageing management. Additionally it offers improvements of all preventive maintenance issues as maintenance periods and the component related volume, spare parts management and costs. (author)

  5. Optimal maintenance policy for a system subject to damage in a discrete time process

    Chien, Yu-Hung; Sheu, Shey-Huei; Zhang, Zhe George

    2012-01-01

    Consider a system operating over n discrete time periods (n=1, 2, …). Each operation period causes a random amount of damage to the system which accumulates over time periods. The system fails when the cumulative damage exceeds a failure level ζ and a corrective maintenance (CM) action is immediately taken. To prevent such a failure, a preventive maintenance (PM) may be performed. In an operation period without a CM or PM, a regular maintenance (RM) is conducted at the end of that period to maintain the operation of the system. We propose a maintenance policy which prescribes a PM when the accumulated damage exceeds a pre-specified level δ ( ⁎ and N ⁎ and discuss some useful properties about them. It has been shown that a δ-based PM outperforms a N-based PM in terms of cost minimization. Numerical examples are presented to demonstrate the optimization of this class of maintenance policies.

  6. An optimal maintenance policy for machine replacement problem using dynamic programming

    Mohsen Sadegh Amalnik; Morteza Pourgharibshahi

    2017-01-01

    In this article, we present an acceptance sampling plan for machine replacement problem based on the backward dynamic programming model. Discount dynamic programming is used to solve a two-state machine replacement problem. We plan to design a model for maintenance by consid-ering the quality of the item produced. The purpose of the proposed model is to determine the optimal threshold policy for maintenance in a finite time horizon. We create a decision tree based on a sequential sampling inc...

  7. Scientific and technological basis for maintenance optimization, planning, testing and monitoring for NPP with WWER

    Kovrizhkin, Yu.L.; Skalozubov, V.I.; Kochneva, V.Yu.

    2009-01-01

    The main results of the developments in the sphere of NPPs with WWER production efficiency increasing by the way of the maintenance optimization planning, testing and monitoring of the equipment and systems are shown. The attention is paid to the metal control during maintenance period of Power Unit. The realization methods of the transition concept at the repair according to the technical condition are resulted

  8. Joint optimization of LORA and spares stocks considering corrective maintenance time

    Linhan Guo; Jiujiu Fan; Meilin Wen; Rui Kang

    2015-01-01

    Level of repair analysis (LORA) is an important method of maintenance decision for establishing systems of operation and maintenance in the equipment development period. Currently, the research on equipment of repair level focuses on economic analy-sis models which are used to optimize costs and rarely considers the maintenance time required by the implementation of the main-tenance program. In fact, as to the system requiring high mission complete success, the maintenance time is an important factor which has a great influence on the availability of equipment sys-tems. Considering the relationship between the maintenance time and the spares stocks level, it is obvious that there are contra-dictions between the maintenance time and the cost. In order to balance these two factors, it is necessary to build an optimization LORA model. To this end, the maintenance time representing per-formance characteristic is introduced, and on the basis of spares stocks which is traditional y regarded as a decision variable, a de-cision variable of repair level is added, and a multi-echelon multi-indenture (MEMI) optimization LORA model is built which takes the best cost-effectiveness ratio as the criterion, the expected num-ber of backorder (EBO) as the objective function and the cost as the constraint. Besides, the paper designs a convex programming algorithm of multi-variable for the optimization model, provides solutions to the non-convex objective function and methods for improving the efficiency of the algorithm. The method provided in this paper is proved to be credible and effective according to the numerical example and the simulation result.

  9. Implementing risk-informed life-cycle design

    Hill, Ralph S.

    2009-01-01

    This paper describes a design process based on risk-informed probabilistic design methodologies that cover a facility's life-cycle from start of conceptual design through decontamination and decommissioning. The concept embodies use of probabilistic risk assessments to establish target reliabilities for facility systems and components. The target reliabilities are used for system based code margin exchange and performance simulation analyses to optimize design over all phases (design, construction, operation and decommissioning) of a facility's life-cycle. System based code margin exchange reduces excessive level of construction margins for passive components to appropriate levels resulting in a more flexible structure of codes and standards that improves facility reliability and cost. System and subsystem simulation analyses determine the optimum combination of initial system and component construction reliability, maintenance frequency, and inspection frequency for both active and passive components. The paper includes a description of these risk-informed life-cycle design processes, a summary of work being done, and a discussion of additional work needed to implement the process.

  10. Contribution to the Optimization of Strategy of Maintenance by Lean Six Sigma

    Youssouf, Ayadi; Rachid, Chaib; Ion, Verzea

    The efficiency of the maintenance of the industrial systems is a major economic stake for their business concern. The main difficulties and the sources of ineffectiveness live in the choice of the actions of maintenance especially when the machine plays a vital role in the process of production. But as Algeria has embarked on major infrastructure projects in transport, housing, automobile, manufacturing industry and construction (factories, housing, highway, subway, tram, etc.) requiring new implications on maintenance strategies that meet industry requirements imposed by the exploitation. From then on and seen the importance of the maintenance on the economic market and sound impacts on the performances of the installations, methods of optimization were developed. For this purpose, to ensure the survival of businesses, be credible, contributing and competitive in the market, maintenance services must continually adapt to the progress of technical areas, technological and organizational even help maintenance managers to construct or to modify maintenance strategies, objective of this work. Our contribution in this work focuses on the optimization of maintenance for industrial systems by the use of Lean six Sigma bases. Lean Six Sigma is a method of improving the quality and profitability based on mastering statically of process and it is also a management style that based on a highly regulated organization dedicated to managing project. The method is based on five main steps summarized in the acronym (DMAIC): Define Measure, Analyze, Improve and Control. Application of the method on the maintenance processes with using maintenance methods during the five phases of the method will help to reduce costs and losses in order to strive for optimum results in terms of profit and quality.

  11. Application of Bayesian statistical decision theory for a maintenance optimization problem

    Procaccia, H.; Cordier, R.; Muller, S.

    1997-01-01

    Reliability-centered maintenance (RCM) is a rational approach that can be used to identify the equipment of facilities that may turn out to be critical with respect to safety, to availability, or to maintenance costs. Is is dor these critical pieces of equipment alone that a corrective (one waits for a failure) or preventive (the type and frequency are specified) maintenance policy is established. But this approach has limitations: - when there is little operating feedback and it concerns rare events affecting a piece of equipment judged critical on a priori grounds (how is it possible, in this case, to decide whether or not it is critical, since there is conflict between the gravity of the potential failure and its frequency?); - when the aim is propose an optimal maintenance frequency for a critical piece of equipment - changing the maintenance frequency hitherto applied may cause a significant drift in the observed reliability of the equipment, an aspect not generally taken into account in the RCM approach. In these two situations, expert judgments can be combined with the available operating feedback (Bayesian approach) and the combination of risk of failure and economic consequences taken into account (statistical decision theory) to achieve a true optimization of maintenance policy choices. This paper presents an application on the maintenance of diesel generator component

  12. Optimal post-warranty maintenance policy with repair time threshold for minimal repair

    Park, Minjae; Mun Jung, Ki; Park, Dong Ho

    2013-01-01

    In this paper, we consider a renewable minimal repair–replacement warranty policy and propose an optimal maintenance model after the warranty is expired. Such model adopts the repair time threshold during the warranty period and follows with a certain type of system maintenance policy during the post-warranty period. As for the criteria for optimality, we utilize the expected cost rate per unit time during the life cycle of the system, which has been frequently used in many existing maintenance models. Based on the cost structure defined for each failure of the system, we formulate the expected cost rate during the life cycle of the system, assuming that a renewable minimal repair–replacement warranty policy with the repair time threshold is provided to the user during the warranty period. Once the warranty is expired, the maintenance of the system is the user's sole responsibility. The life cycle of the system is defined on the perspective of the user and the expected cost rate per unit time is derived in this context. We obtain the optimal maintenance policy during the maintenance period following the expiration of the warranty period by minimizing such a cost rate. Numerical examples using actual failure data are presented to exemplify the applicability of the methodologies proposed in this paper.

  13. Optimal manpower allocation in aircraft line maintenance (Case in GMF AeroAsia)

    Puteri, V. E.; Yuniaristanto, Hisjam, M.

    2017-11-01

    This paper presents a mathematical modeling to find the optimal manpower allocation in an aircraft line maintenance. This research focuses on assigning the number and type of manpower that allocated to each service. This study considers the licenced worker or Aircraft Maintenance Engineer Licence (AMEL) and non licenced worker or Aircraft Maintenance Technician (AMT). In this paper, we also consider the relationship of each station in terms of the possibility to transfer the manpower among them. The optimization model considers the number of manpowers needed for each service and the requirement of AMEL worker. This paper aims to determine the optimal manpower allocation using the mathematical modeling. The objective function of the model is to find the minimum employee expenses. The model was solved using the ILOG CPLEX software. The results show that the manpower allocation can meet the manpower need and the all load can be served.

  14. Optimizing production and imperfect preventive maintenance planning's integration in failure-prone manufacturing systems

    Aghezzaf, El-Houssaine; Khatab, Abdelhakim; Tam, Phuoc Le

    2016-01-01

    This paper investigates the issue of integrating production and maintenance planning in a failure-prone manufacturing system. It is assumed that the system's operating state is stochastically predictable, in terms of its operating age, and that it can accordingly be preventively maintained during preplanned periods. Preventive maintenance is assumed to be imperfect, that is when performed, it brings the manufacturing system to an operating state that lies between ‘as bad as old’ and ‘as good as new’. Only an overhauling of the system brings it to a ‘as good as new’ operating state again. A practical integrated production and preventive maintenance planning model, that takes into account the system's manufacturing capacity and its operational reliability state, is developed. The model is naturally formulated as a mixed-integer non-linear optimization problem, for which an extended mixed-integer linear reformulation is proposed. This reformulation, while it solves the proposed integrated planning problem to optimality, remains quite demanding in terms of computational time. A fix-and-optimize procedure, that takes advantage of some properties of the original model, is then proposed. The reformulation and the fix-and-optimize procedure are tested on some test instances adapted from those available in the literature. The results show that the proposed fix-and-optimize procedure performs quite well and opens new research direction for future improvements. - Highlights: • Integration of production planning and imperfect preventive maintenance is explored. • Imperfect maintenance is modeled using a fitting age reduction hybrid hazard rate. • A practical approximate optimization model for this integration is proposed. • The resulting naturally MINL optimization model is reformulated and solved as a MILP. • An effective fix-and-optimize procedure is proposed for large instances of this MILP.

  15. A review on condition-based maintenance optimization models for stochastically deteriorating system

    Alaswad, Suzan; Xiang, Yisha

    2017-01-01

    Condition-based maintenance (CBM) is a maintenance strategy that collects and assesses real-time information, and recommends maintenance decisions based on the current condition of the system. In recent decades, research on CBM has been rapidly growing due to the rapid development of computer-based monitoring technologies. Research studies have proven that CBM, if planned properly, can be effective in improving equipment reliability at reduced costs. This paper presents a review of CBM literature with emphasis on mathematical modeling and optimization approaches. We focus this review on important aspects of the CBM, such as optimization criteria, inspection frequency, maintenance degree, solution methodology, etc. Since the modeling choice for the stochastic deterioration process greatly influences CBM strategy decisions, this review classifies the literature on CBM models based on the underlying deterioration processes, namely discrete- and continuous-state deterioration, and proportional hazard model. CBM models for multi-unit systems are also reviewed in this paper. This paper provides useful references for CBM management professionals and researchers working on CBM modeling and optimization. - Highlights: • A review on Condition-based maintenance (CBM) optimization models is presented. • The CBM models are classified based on the underlying deterioration processes. • Existing CBM models for both single- and multi-unit systems are reviewed. • Future essential research directions on CBM are identified.

  16. Preventive maintenance optimization for a multi-component system under changing job shop schedule

    Zhou Xiaojun; Lu Zhiqiang; Xi Lifeng

    2012-01-01

    Variability and small lot size is a common feature for many discrete manufacturing processes designed to meet a wide array of customer needs. Because of this, job shop schedule often has to be continuously updated in reaction to changes in production plan. Generally, the aim of preventive maintenance is to ensure production effectiveness and therefore the preventive maintenance models must have the ability to be adaptive to changes in job shop schedule. In this paper, a dynamic opportunistic preventive maintenance model is developed for a multi-component system with considering changes in job shop schedule. Whenever a job is completed, preventive maintenance opportunities arise for all the components in the system. An optimal maintenance practice is dynamically determined by maximizing the short-term cumulative opportunistic maintenance cost savings for the system. The numerical example shows that the scheme obtained by the proposed model can effectively address the preventive maintenance scheduling problem caused by the changes in job shop schedule and is more efficient than the ones based on two other commonly used preventive maintenance models.

  17. Maintenance Optimization for Offshore Wind Turbines using POMDP

    Nielsen, Jannie Sønderkær; Sørensen, John Dalsgaard

    2012-01-01

    programming can be used. Seasonal weather variations are included through their influence on weather constrains for inspections and repairs, as well as costs to lost production, when corrective repair is not possible after failure. Application of the model is illustrated through an example, where the main...... bearing is considered. Optimization is initially performed for one component, and decision making for an entire wind farm is considered by using revised decision policies, when mobilization costs are already paid for another repair. The total costs are calculated for an entire wind farm using simulation...

  18. On test and maintenance: Optimization of allowed outage time

    Mavko, B.; Cepin, M.T.

    2000-01-01

    Probabilistic Safety Assessment is widely becoming standard method for assessing, maintaining, assuring and improving the nuclear power plant safety. To achieve one of its many potential benefits, the optimization of allowed outage time specified in technical specifications is investigated. Proposed is the risk comparison approach for evaluation of allowed outage time. The risk of shutting the plant down due to failure of certain equipment is compared to the risk of continued plant operation with the specified equipment down. The core damage frequency serves as a risk measure. (author)

  19. The LifeCycle model

    Krink, Thiemo; Løvbjerg, Morten

    2002-01-01

    genetic algorithms (GAs), particle swarm optimisation (PSOs), and stochastic hill climbing to create a generally well-performing search heuristics. In the LifeCycle model, we consider candidate solutions and their fitness as individuals, which, based on their recent search progress, can decide to become...... either a GA individual, a particle of a PSO, or a single stochastic hill climber. First results from a comparison of our new approach with the single search algorithms indicate a generally good performance in numerical optimization....

  20. Multiobjective Optimization of Aircraft Maintenance in Thailand Using Goal Programming: A Decision-Support Model

    Yuttapong Pleumpirom

    2012-01-01

    Full Text Available The purpose of this paper is to develop the multiobjective optimization model in order to evaluate suppliers for aircraft maintenance tasks, using goal programming. The authors have developed a two-step process. The model will firstly be used as a decision-support tool for managing demand, by using aircraft and flight schedules to evaluate and generate aircraft-maintenance requirements, including spare-part lists. Secondly, they develop a multiobjective optimization model by minimizing cost, minimizing lead time, and maximizing the quality under various constraints in the model. Finally, the model is implemented in the actual airline's case.

  1. An Aircraft Lifecycle Approach for the Cost-Benefit Analysis of Prognostics and Condition-Based Maintenance-Based on Discrete-Event Simulation

    2014-10-02

    MPD. This manufacturer documentation contains maintenance tasks with specification of intervals and required man-hours that are to be carried out...failures, without consideration of false alarms and missed failures (see also section 4.1.3). The task redundancy rate is the percentage of preventive...Prognostics and Health Management ROI return on investment RUL remaining useful life TCG task code group SB Service Bulletin XML Extensible Markup

  2. Streamline Your Project: A Lifecycle Model.

    Viren, John

    2000-01-01

    Discusses one approach to project organization providing a baseline lifecycle model for multimedia/CBT development. This variation of the standard four-phase model of Analysis, Design, Development, and Implementation includes a Pre-Analysis phase, called Definition, and a Post-Implementation phase, known as Maintenance. Each phase is described.…

  3. A sustainable life-cycle method

    Diruji Dugarte

    2015-07-01

    Full Text Available The need for innovative and cost effective approaches for infrastructure maintenance has never been more crucial. In fact, this has been a popular topic in technical reports like the McGraw Hill Construction, the Dutch Cobouw construction magazine and the new multidisciplinary journal “Infrastructure Asset Management” by the Institution of Civil Engineers. The financial status of Industrial Parks (IP and Business Parks (BP in the Netherlands, as well as in the rest of the world, has been greatly influenced by the 2007-2008 financial crisis. As a consequence, several IPs and BPs have suffered from infrastructural deterioration that needs to be revitalized. Therefore, one of the priorities facing municipalities nowadays is stimulating companies to invest and redefine such areas with the goal of improving its economic output and optimize the expenditure on its maintenance costs. The different stakeholders involved in the life-cycle management of these parks make strategic decisions based on data that has been gathered over time by its users, either private or public. However, gathering data is becoming more and more complex with time. Infrastructures in these parks are increasingly demanding custom supply of services by the private industry to cope with their technical operations. As a consequence, the level of detail of the assets information is very high. Hence, the digital collaboration and interoperability has become almost mandatory for enabling proper management in construction areas. Interoperability can be described as the ability of making systems and organization work together.

  4. A two-stage preventive maintenance optimization model incorporating two-dimensional extended warranty

    Su, Chun; Wang, Xiaolin

    2016-01-01

    In practice, customers can decide whether to buy an extended warranty or not, at the time of item sale or at the end of the basic warranty. In this paper, by taking into account the moments of customers purchasing two-dimensional extended warranty, the optimization of imperfect preventive maintenance for repairable items is investigated from the manufacturer's perspective. A two-dimensional preventive maintenance strategy is proposed, under which the item is preventively maintained according to a specified age interval or usage interval, whichever occurs first. It is highlighted that when the extended warranty is purchased upon the expiration of the basic warranty, the manufacturer faces a two-stage preventive maintenance optimization problem. Moreover, in the second stage, the possibility of reducing the servicing cost over the extended warranty period is explored by classifying customers on the basis of their usage rates and then providing them with customized preventive maintenance programs. Numerical examples show that offering customized preventive maintenance programs can reduce the manufacturer's warranty cost, while a larger saving in warranty cost comes from encouraging customers to buy the extended warranty at the time of item sale. - Highlights: • A two-dimensional PM strategy is investigated. • Imperfect PM strategy is optimized by considering both two-dimensional BW and EW. • Customers are categorized based on their usage rates throughout the BW period. • Servicing cost of the EW is reduced by offering customized PM programs. • Customers buying the EW at the time of sale is preferred for the manufacturer.

  5. Multiobjective Joint Optimization of Production Scheduling and Maintenance Planning in the Flexible Job-Shop Problem

    Jianfei Ye

    2015-01-01

    Full Text Available In order to solve the joint optimization of production scheduling and maintenance planning problem in the flexible job-shop, a multiobjective joint optimization model considering the maximum completion time and maintenance costs per unit time is established based on the concept of flexible job-shop and preventive maintenance. A weighted sum method is adopted to eliminate the index dimension. In addition, a double-coded genetic algorithm is designed according to the problem characteristics. The best result under the circumstances of joint decision-making is obtained through multiple simulation experiments, which proves the validity of the algorithm. We can prove the superiority of joint optimization model by comparing the result of joint decision-making project with the result of independent decision-making project under fixed preventive maintenance period. This study will enrich and expand the theoretical framework and analytical methods of this problem; it provides a scientific decision analysis method for enterprise to make production plan and maintenance plan.

  6. Geometric Process-Based Maintenance and Optimization Strategy for the Energy Storage Batteries

    Yan Li

    2016-01-01

    Full Text Available Renewable energy is critical for improving energy structure and reducing environment pollution. But its strong fluctuation and randomness have a serious effect on the stability of the microgrid without the coordination of the energy storage batteries. The main factors that influence the development of the energy storage system are the lack of valid operation and maintenance management as well as the cost control. By analyzing the typical characteristics of the energy storage batteries in their life cycle, the geometric process-based model including the deteriorating system and the improving system is firstly built for describing the operation process, the preventive maintenance process, and the corrective maintenance process. In addition, this paper proposes an optimized management strategy, which aims to minimize the long-run average cost of the energy storage batteries by defining the time interval of the detection and preventive maintenance process as well as the optimal corrective maintenance times, subjected to the state of health and the reliability conditions. The simulation is taken under the built model by applying the proposed energy storage batteries’ optimized management strategy, which verifies the effectiveness and applicability of the management strategy, denoting its obvious practicality on the current application.

  7. A maintenance optimization model for mission-oriented systems based on Wiener degradation

    Guo, Chiming; Wang, Wenbin; Guo, Bo; Si, Xiaosheng

    2013-01-01

    Over the past few decades, condition-based maintenance (CBM) has attracted many researchers because of its effectiveness and practical significance. This paper deals with mission-oriented systems subject to gradual degradation modeled by a Wiener stochastic process within the context of CBM. For a mission-oriented system, the mission usually has constraints on availability/reliability, the opportunity for maintenance actions, and the monitoring type (continuous or discrete). Furthermore, in practice, a mission-oriented system may undertake some preventive maintenance (PM) and after such PM, the system may return to an intermediate state between an as-good-as new state and an as-bad-as old state, i.e., the PM is not perfect and only partially restores the system. However, very few CBM models integrated these mission constraints together with an imperfect nature of the PM into the course of optimizing the PM policy. This paper develops a model to optimize the PM policy in terms of the maintenance related cost jointly considering the mission constraints and the imperfect PM nature. A numerical example is presented to demonstrate the proposed model. The comparison with the simulated results and the sensitivity analysis show the usefulness of the optimization model for mission-oriented system maintenance presented in this paper.

  8. Improved quality of input data for maintenance optimization using expert judgment

    Oien, Knut

    1998-01-01

    Most maintenance optimization models need an estimate of the so-called 'naked' failure rate function as input. In practice it is very difficult to estimate the 'naked' failure rate, because overhauls and other preventive maintenance actions tend to 'corrupt' the recorded lifelengths. The purpose of this paper is to stress the importance of utilizing the knowledge of maintenance engineers, i.e., expert judgment, in addition to recorded equipment lifelengths, in order to get credible input data. We have shown that without utilizing expert judgment, the estimated mean time to failure may be strongly biased, often by a factor of 2-3, depending on the life distribution that is assumed. We recommend including a simple question about the mean remaining lifelength on the work-order forms. By this approach the knowledge of maintenance engineers may be incorporated in a simple and cost-effective way

  9. Optimal maintenance policy incorporating system level and unit level for mechanical systems

    Duan, Chaoqun; Deng, Chao; Wang, Bingran

    2018-04-01

    The study works on a multi-level maintenance policy combining system level and unit level under soft and hard failure modes. The system experiences system-level preventive maintenance (SLPM) when the conditional reliability of entire system exceeds SLPM threshold, and also undergoes a two-level maintenance for each single unit, which is initiated when a single unit exceeds its preventive maintenance (PM) threshold, and the other is performed simultaneously the moment when any unit is going for maintenance. The units experience both periodic inspections and aperiodic inspections provided by failures of hard-type units. To model the practical situations, two types of economic dependence have been taken into account, which are set-up cost dependence and maintenance expertise dependence due to the same technology and tool/equipment can be utilised. The optimisation problem is formulated and solved in a semi-Markov decision process framework. The objective is to find the optimal system-level threshold and unit-level thresholds by minimising the long-run expected average cost per unit time. A formula for the mean residual life is derived for the proposed multi-level maintenance policy. The method is illustrated by a real case study of feed subsystem from a boring machine, and a comparison with other policies demonstrates the effectiveness of our approach.

  10. Using risk-informed asset management for feedwater system preventative maintenance optimization

    Kee, Ernest; Sun, Alice; Richards, Andrew; Grantom, Rick; Liming, James; Salter, James

    2004-01-01

    The initial development of a South Texas Project Nuclear Operating Company process for supporting preventative maintenance optimization by applying the Balance-Of-Plant model and Risk-Informed Asset Management alpha-level software applications is presented. Preventative maintenance activities are evaluated in the South Texas Project Risk-Informed Asset Management software while the plant maintains or improves upon high levels of nuclear safety. In the Balance-Of-Plant availability application, the level of detail in the feedwater system is enhanced to support plant decision-making at the component failure mode and human error mode level of indenture by elaborating on the current model at the super-component level of indenture. The enhanced model and modeling techniques are presented. Results of case studies in feedwater system preventative maintenance optimization sing plant-specific data are also presented. (author)

  11. Reliability centered maintenance as an optimization tool for electrical power plants

    Jacquot, J.P.; Bryla, P.; Martin-Mattei, C.; Meuwisse, C.

    1997-08-01

    Seven years ago, Electricite de France launched a Reliability Centered Maintenance (RCM) pilot project to optimize preventive maintenance for its nuclear power plants. After a feasibility study, a RCM method was standardized. It is now applied on a large scale to the 50 EDF nuclear units. A RCM workstation based on this standardized method has been developed and is now used in each plant. In the next step, it is considered whether a Risk based Approach can be included in this RCM process in order to analyze critical passive components such as pipes and supports. Considering the potential advantages of these optimization techniques, a dedicated process has been also developed for maintenance of future plants, gas turbines, or nuclear units. A survey of these different developments of methods and tools is presented. (author)

  12. Joint optimization of condition-based maintenance and production lot-sizing

    Peng, H.; van Houtum, G.J.J.A.N.

    2016-01-01

    Due to the development of sensor technologies nowadays, condition-based maintenance (CBM) programs can be established and optimized based on the data collected through condition monitoring. The CBM activities can significantly increase the uptime of a machine. However, they should be conducted in a

  13. Optimization of maintenance for power system equipment using a predictive health model

    Bajracharya, G.; Koltunowicz, T.; Negenborn, R.R.; Papp, Z.; Djairam, D.; Schutter, B.D. de; Smit, J.J.

    2009-01-01

    In this paper, a model-predictive control based framework is proposed for modeling and optimization of the health state of power system equipment. In the framework, a predictive health model is proposed that predicts the health state of the equipment based on its usage and maintenance actions. Based

  14. An Enhanced Preventive Maintenance Optimization Model Based on a Three-Stage Failure Process

    Ruifeng Yang

    2015-01-01

    Full Text Available Nuclear power plants are highly complex systems and the issues related to their safety are of primary importance. Probabilistic safety assessment is regarded as the most widespread methodology for studying the safety of nuclear power plants. As maintenance is one of the most important factors for affecting the reliability and safety, an enhanced preventive maintenance optimization model based on a three-stage failure process is proposed. Preventive maintenance is still a dominant maintenance policy due to its easy implementation. In order to correspond to the three-color scheme commonly used in practice, the lifetime of system before failure is divided into three stages, namely, normal, minor defective, and severe defective stages. When the minor defective stage is identified, two measures are considered for comparison: one is that halving the inspection interval only when the minor defective stage is identified at the first time; the other one is that if only identifying the minor defective stage, the subsequent inspection interval is halved. Maintenance is implemented immediately once the severe defective stage is identified. Minimizing the expected cost per unit time is our objective function to optimize the inspection interval. Finally, a numerical example is presented to illustrate the effectiveness of the proposed models.

  15. An Optimization Method for Condition Based Maintenance of Aircraft Fleet Considering Prognostics Uncertainty

    Qiang Feng

    2014-01-01

    Full Text Available An optimization method for condition based maintenance (CBM of aircraft fleet considering prognostics uncertainty is proposed. The CBM and dispatch process of aircraft fleet is analyzed first, and the alternative strategy sets for single aircraft are given. Then, the optimization problem of fleet CBM with lower maintenance cost and dispatch risk is translated to the combinatorial optimization problem of single aircraft strategy. Remain useful life (RUL distribution of the key line replaceable Module (LRM has been transformed into the failure probability of the aircraft and the fleet health status matrix is established. And the calculation method of the costs and risks for mission based on health status matrix and maintenance matrix is given. Further, an optimization method for fleet dispatch and CBM under acceptable risk is proposed based on an improved genetic algorithm. Finally, a fleet of 10 aircrafts is studied to verify the proposed method. The results shows that it could realize optimization and control of the aircraft fleet oriented to mission success.

  16. An optimal maintenance policy for machine replacement problem using dynamic programming

    Mohsen Sadegh Amalnik

    2017-06-01

    Full Text Available In this article, we present an acceptance sampling plan for machine replacement problem based on the backward dynamic programming model. Discount dynamic programming is used to solve a two-state machine replacement problem. We plan to design a model for maintenance by consid-ering the quality of the item produced. The purpose of the proposed model is to determine the optimal threshold policy for maintenance in a finite time horizon. We create a decision tree based on a sequential sampling including renew, repair and do nothing and wish to achieve an optimal threshold for making decisions including renew, repair and continue the production in order to minimize the expected cost. Results show that the optimal policy is sensitive to the data, for the probability of defective machines and parameters defined in the model. This can be clearly demonstrated by a sensitivity analysis technique.

  17. Development of a standard methodology for optimizing remote visual display for nuclear maintenance tasks

    Clarke, M. M.; Garin, J.; Prestonanderson, A.

    A fuel recycle facility being designed at Oak Ridge National Laboratory involves the Remotex concept: advanced servo-controlled master/slave manipulators, with remote television viewing, will totally replace direct human contact with the radioactive environment. The design of optimal viewing conditions is a critical component of the overall man/machine system. A methodology was developed for optimizing remote visual displays for nuclear maintenance tasks. The usefulness of this approach was demonstrated by preliminary specification of optimal closed circuit TV systems for such tasks.

  18. Dynamic optimization of maintenance and improvement planning for water main system: Periodic replacement approach

    Kim, Jong Woo; Choi, Go Bong; Lee, Jong Min [Seoul National University, Seoul (Korea, Republic of); Suh, Jung Chul [Samchully Corporation, Seoul (Korea, Republic of)

    2016-01-15

    This paper proposes a Markov decision process (MDP) based approach to derive an optimal schedule of maintenance, rehabilitation and replacement of the water main system. The scheduling problem utilizes auxiliary information of a pipe such as the current state, cost, and deterioration model. The objective function and detailed algorithm of dynamic programming are modified to solve the periodic replacement problem. The optimal policy evaluated by the proposed algorithm is compared to several existing policies via Monte Carlo simulations. The proposed decision framework provides a systematic way to obtain an optimal policy.

  19. Inventory-transportation integrated optimization for maintenance spare parts of high-speed trains

    Wang, Jiaxi; Wang, Huasheng; Wang, Zhongkai; Li, Jian; Lin, Ruixi; Xiao, Jie; Wu, Jianping

    2017-01-01

    This paper presents a 0–1 programming model aimed at obtaining the optimal inventory policy and transportation mode for maintenance spare parts of high-speed trains. To obtain the model parameters for occasionally-replaced spare parts, a demand estimation method based on the maintenance strategies of China’s high-speed railway system is proposed. In addition, we analyse the shortage time using PERT, and then calculate the unit time shortage cost from the viewpoint of train operation revenue. Finally, a real-world case study from Shanghai Depot is conducted to demonstrate our method. Computational results offer an effective and efficient decision support for inventory managers. PMID:28472097

  20. Application of probabilistic fracture mechanics to optimize the maintenance of PWR steam generator tubes

    Pitner, P.; Riffard, T.

    1993-09-01

    This paper describes the COMPROMIS code developed by Electricite de France (EDF) to optimize the tube bundle maintenance of steam generators (SG). The model, based on probabilistic fracture mechanics, makes it possible to quantify the influence of in-service inspections and maintenance work on the risk of an SG tube rupture, taking all significant parameters into account as random variables (initial defect size distribution, reliability of nondestructive detection and sizing, crack initiation and propagation, critical sizes, leak before risk of break, etc). (authors). 14 figs., 4 tabs., 12 refs

  1. Application of Bayesian statistical decision theory to the optimization of generating set maintenance

    Procaccia, H.; Cordier, R.; Muller, S.

    1994-07-01

    Statistical decision theory could be a alternative for the optimization of preventive maintenance periodicity. In effect, this theory concerns the situation in which a decision maker has to make a choice between a set of reasonable decisions, and where the loss associated to a given decision depends on a probabilistic risk, called state of nature. In the case of maintenance optimization, the decisions to be analyzed are different periodicities proposed by the experts, given the observed feedback experience, the states of nature are the associated failure probabilities, and the losses are the expectations of the induced cost of maintenance and of consequences of the failures. As failure probabilities concern rare events, at the ultimate state of RCM analysis (failure of sub-component), and as expected foreseeable behaviour of equipment has to be evaluated by experts, Bayesian approach is successfully used to compute states of nature. In Bayesian decision theory, a prior distribution for failure probabilities is modeled from expert knowledge, and is combined with few stochastic information provided by feedback experience, giving a posterior distribution of failure probabilities. The optimized decision is the decision that minimizes the expected loss over the posterior distribution. This methodology has been applied to inspection and maintenance optimization of cylinders of diesel generator engines of 900 MW nuclear plants. In these plants, auxiliary electric power is supplied by 2 redundant diesel generators which are tested every 2 weeks during about 1 hour. Until now, during yearly refueling of each plant, one endoscopic inspection of diesel cylinders is performed, and every 5 operating years, all cylinders are replaced. RCM has shown that cylinder failures could be critical. So Bayesian decision theory has been applied, taking into account expert opinions, and possibility of aging when maintenance periodicity is extended. (authors). 8 refs., 5 figs., 1 tab

  2. Model of the Product Development Lifecycle.

    He, Sunny L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Roe, Natalie H. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Wood, Evan [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Nachtigal, Noel M. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Helms, Jovana [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-10-01

    While the increased use of Commercial Off-The-Shelf information technology equipment has presented opportunities for improved cost effectiveness and flexibility, the corresponding loss of control over the product's development creates unique vulnerabilities and security concerns. Of particular interest is the possibility of a supply chain attack. A comprehensive model for the lifecycle of hardware and software products is proposed based on a survey of existing literature from academic, government, and industry sources. Seven major lifecycle stages are identified and defined: (1) Requirements, (2) Design, (3) Manufacturing for hardware and Development for software, (4) Testing, (5) Distribution, (6) Use and Maintenance, and (7) Disposal. The model is then applied to examine the risk of attacks at various stages of the lifecycle.

  3. Ageing of reinforced concrete pipes subjected to seawater in nuclear plants: optimization of maintenance operations

    Auge, L.; Capra, B.; Lasne, M.; Benefice, P.; Comby, R.

    2007-01-01

    Seaside nuclear power plants have to face the ageing of nuclear reactor cooling piping systems. In order to minimize the duration of the production unit shutdown, maintenance operations have to be planned well in advance. In a context where owners of infrastructures tend to extend the life span of their goods while having to keep the safety level maximum, it is more and more important to develop high level expertise and know-how in management of infrastructures life cycle. A patented monitoring technique based on optic fiber sensors, has been designed. This preventive maintenance enables the owner to determine criteria for network replacement based on degradation impacts. A methodology to evaluate and optimize operation budgets, depending on predictions of future functional deterioration and available maintenance solutions, has been developed and applied. (authors)

  4. Maintenance in sustainable manufacturing

    Vladimir Stuchly

    2014-09-01

    Full Text Available Background: Sustainable development is about reaching a balance between economic, social, and environmental goals, as well as people's participation in the planning process in order to gain their input and support. For a company, sustainable development means adoption of such business strategy and actions that contribute to satisfying present needs of company and stakeholders, as well as simultaneous protection, maintenance and strengthening of human and environmental potential which will be needed in the future. This new approach forces manufacturing companies to change their previous management paradigms. New management paradigm should include new issues and develop innovative methods, practices and technologies striving for solving problem of shortages of resources, softening environment overload and enabling development of environment-friendly lifecycle of products. Hence, its realization requires updating existing production models as they are based on previously accepted paradigm of unlimited resources and unlimited regeneration capabilities. Maintenance plays a crucial role because of its impact on availability, reliability, quality and life cycle cost, thus it should be one of the main pillars of new business running model.  Material and methods: The following paper is a result of research on the literature and observation of practices undertaken by a company within maintenance area. Results and conclusions: The main message is that considering sustainable manufacturing requires considerable expanding range of analysis and focusing on supporting processes. Maintenance offers numerous opportunities of decreasing influence of business processes on natural environment and more efficient resources utilization. The goal of maintenance processes realizing sustainable development strategy is increased profitability of exploitation and optimization of total lifecycle cost without disturbing safety and environmental issues. 

  5. Integer 1/0 Knapsack Problem Dynamic Programming Approach in Building Maintenance Optimization

    Viska Dewi Fawzy

    2017-12-01

    Full Text Available The most common problem in urban areas is the high public demand and the limited provision of housing. In meeting the needs of affordable housing for low income communities, the Government of Indonesia implements Rusunawa Project. Object of this research is Pandanarang Rusunawa. Rusunawa Pandanarang is one of the vertical housing in Cilacap that is facing deterioration issue and needs good maintenance management. This study aims at insetting priority and optimizing maintenance plan due to limited funds (limited budget and the amount of damage that must be repaired.This study uses one of the optimization methods of Dynamic Programing on the application of Integer 1/0 Knapsack Problem, to determine an schedule the maintenance activities. The Criteria that are used such as: the level of building components damage and the level of occupants participation. In the first criterion, the benefit (p is the percentage of damage that is fixed with the cost (w. While on the second criterion, the benefit (p is the percentage of occupant participation rate on the maintenance activities with the cost (w. For the budget of Rp 125.000.000, 00, it was obtained from the simulation that the value of the optimum solution on the first criterion at the 7th stage of 71.88% with total cost Rp 106.000.000, 00. At the second criterion, the value of the optimum solution at the 7th stage of 89.29% with total cost Rp 124.000.000, 00.

  6. BINARY PARTICLE SWARM OPTIMIZATION APPROACH FOR RANDOM GENERATION OUTAGE MAINTENANCE SCHEDULING

    K. Suresh

    2013-01-01

    Full Text Available This paper presents a methodology for maintenance scheduling (MS of generators using binary particle swarm optimization (BPSO based probabilistic approach. The objective of this paper is to reduce the loss of load probability (LOLP for a power system. The capacity outage probability table (COPT is the initial step in creating maintenance schedule using the probabilistic levelized risk method. This paper proposes BPSO method which is used to construct the COPT. In order to mitigate the effects of probabilistic levelized risk method, BPSO based probabilistic levelized risk method is embarked on a MS problem. In order to validate the effectiveness of the proposed algorithm, case study results for simple five unit system can accomplish a significant levelization in the reliability indices that make possible to evaluate system generation system adequacy in the MS horizon of the power system. The proposed method shows better performance compared with other optimization methods and conventional method with improved search performance.

  7. Optimizing maintenance and repair policies via a combination of genetic algorithms and Monte Carlo simulation

    Marseguerra, M.; Zio, E.

    2000-01-01

    In this paper we present an optimization approach based on the combination of a Genetic Algorithms maximization procedure with a Monte Carlo simulation. The approach is applied within the context of plant logistic management for what concerns the choice of maintenance and repair strategies. A stochastic model of plant operation is developed from the standpoint of its reliability/availability behavior, i.e. of the failure/repair/maintenance processes of its components. The model is evaluated by Monte Carlo simulation in terms of economic costs and revenues of operation. The flexibility of the Monte Carlo method allows us to include several practical aspects such as stand-by operation modes, deteriorating repairs, aging, sequences of periodic maintenances, number of repair teams available for different kinds of repair interventions (mechanical, electronic, hydraulic, etc.), components priority rankings. A genetic algorithm is then utilized to optimize the components maintenance periods and number of repair teams. The fitness function object of the optimization is a profit function which inherently accounts for the safety and economic performance of the plant and whose value is computed by the above Monte Carlo simulation model. For an efficient combination of Genetic Algorithms and Monte Carlo simulation, only few hundreds Monte Carlo histories are performed for each potential solution proposed by the genetic algorithm. Statistical significance of the results of the solutions of interest (i.e. the best ones) is then attained exploiting the fact that during the population evolution the fit chromosomes appear repeatedly many times. The proposed optimization approach is applied on two case studies of increasing complexity

  8. Reliability-based optimization of maintenance scheduling of mechanical components under fatigue

    Beaurepaire, P.; Valdebenito, M.A.; Schuëller, G.I.; Jensen, H.A.

    2012-01-01

    This study presents the optimization of the maintenance scheduling of mechanical components under fatigue loading. The cracks of damaged structures may be detected during non-destructive inspection and subsequently repaired. Fatigue crack initiation and growth show inherent variability, and as well the outcome of inspection activities. The problem is addressed under the framework of reliability based optimization. The initiation and propagation of fatigue cracks are efficiently modeled using cohesive zone elements. The applicability of the method is demonstrated by a numerical example, which involves a plate with two holes subject to alternating stress. PMID:23564979

  9. A decentralized multidistrict optimization framework for system-wide pavement maintenance resource allocation

    J. Farhan

    2016-05-01

    Full Text Available Historically, pavement maintenance funds have been allocated based on a centralized programme development process. Such practice, though seemingly convenient, does not lead to optimal allocation of funds since districts generally have different priorities based on the state of development and condition of their respective road networks. This paper proposes a decentralized two-phased optimization framework for pavement maintenance fund allocation considering multiple objectives and cross-district trade-off at the network level. In the proposed two-phased analysis approach, Phase-I focuses on establishing the needs and funds requirements of individual districts given multiple performance targets or objectives, while a system-wide fund appropriation strategy is selected, in Phase-II, given budget and equity constraints across competing districts. The proposed approach is illustrated using a numerical example problem for appropriating funds to three districts. The results indicated that the proposed approach is not only able to evaluate the extent to which various performance targets are achieved at the central and district level, but also maintains equity in distribution of financial resources across districts. Keywords: Pavement maintenance programming, Multiobjective, Multidistrict, Optimized resource allocation, Genetic algorithm, Dynamic programming

  10. An Optimal Number-Dependent Preventive Maintenance Strategy for Offshore Wind Turbine Blades Considering Logistics

    Mahmood Shafiee

    2013-01-01

    Full Text Available In offshore wind turbines, the blades are among the most critical and expensive components that suffer from different types of damage due to the harsh maritime environment and high load. The blade damages can be categorized into two types: the minor damage, which only causes a loss in wind capture without resulting in any turbine stoppage, and the major (catastrophic damage, which stops the wind turbine and can only be corrected by replacement. In this paper, we propose an optimal number-dependent preventive maintenance (NDPM strategy, in which a maintenance team is transported with an ordinary or expedited lead time to the offshore platform at the occurrence of the Nth minor damage or the first major damage, whichever comes first. The long-run expected cost of the maintenance strategy is derived, and the necessary conditions for an optimal solution are obtained. Finally, the proposed model is tested on real data collected from an offshore wind farm database. Also, a sensitivity analysis is conducted in order to evaluate the effect of changes in the model parameters on the optimal solution.

  11. An iterative approach for the optimization of pavement maintenance management at the network level.

    Torres-Machí, Cristina; Chamorro, Alondra; Videla, Carlos; Pellicer, Eugenio; Yepes, Víctor

    2014-01-01

    Pavement maintenance is one of the major issues of public agencies. Insufficient investment or inefficient maintenance strategies lead to high economic expenses in the long term. Under budgetary restrictions, the optimal allocation of resources becomes a crucial aspect. Two traditional approaches (sequential and holistic) and four classes of optimization methods (selection based on ranking, mathematical optimization, near optimization, and other methods) have been applied to solve this problem. They vary in the number of alternatives considered and how the selection process is performed. Therefore, a previous understanding of the problem is mandatory to identify the most suitable approach and method for a particular network. This study aims to assist highway agencies, researchers, and practitioners on when and how to apply available methods based on a comparative analysis of the current state of the practice. Holistic approach tackles the problem considering the overall network condition, while the sequential approach is easier to implement and understand, but may lead to solutions far from optimal. Scenarios defining the suitability of these approaches are defined. Finally, an iterative approach gathering the advantages of traditional approaches is proposed and applied in a case study. The proposed approach considers the overall network condition in a simpler and more intuitive manner than the holistic approach.

  12. An Iterative Approach for the Optimization of Pavement Maintenance Management at the Network Level

    Cristina Torres-Machí

    2014-01-01

    Full Text Available Pavement maintenance is one of the major issues of public agencies. Insufficient investment or inefficient maintenance strategies lead to high economic expenses in the long term. Under budgetary restrictions, the optimal allocation of resources becomes a crucial aspect. Two traditional approaches (sequential and holistic and four classes of optimization methods (selection based on ranking, mathematical optimization, near optimization, and other methods have been applied to solve this problem. They vary in the number of alternatives considered and how the selection process is performed. Therefore, a previous understanding of the problem is mandatory to identify the most suitable approach and method for a particular network. This study aims to assist highway agencies, researchers, and practitioners on when and how to apply available methods based on a comparative analysis of the current state of the practice. Holistic approach tackles the problem considering the overall network condition, while the sequential approach is easier to implement and understand, but may lead to solutions far from optimal. Scenarios defining the suitability of these approaches are defined. Finally, an iterative approach gathering the advantages of traditional approaches is proposed and applied in a case study. The proposed approach considers the overall network condition in a simpler and more intuitive manner than the holistic approach.

  13. Development of a standard methodology for optimizing remote visual display for nuclear-maintenance tasks

    Clarke, M.M.; Garin, J.; Preston-Anderson, A.

    1981-01-01

    The aim of the present study is to develop a methodology for optimizing remote viewing systems for a fuel recycle facility (HEF) being designed at Oak Ridge National Laboratory (ORNL). An important feature of this design involves the Remotex concept: advanced servo-controlled master/slave manipulators, with remote television viewing, will totally replace direct human contact with the radioactive environment. Therefore, the design of optimal viewing conditions is a critical component of the overall man/machine system. A methodology has been developed for optimizing remote visual displays for nuclear maintenance tasks. The usefulness of this approach has been demonstrated by preliminary specification of optimal closed circuit TV systems for such tasks

  14. Life-Cycle Cost-Benefit (LCCB) Analysis of Bridges from a User and Social Point of View

    Thoft-Christensen, Palle

    2009-01-01

    is to present and discuss some of these problems from a user and social point of view. A brief presentation of a preliminary study of the importance of including benefits in life-cycle cost-benefit analysis in management systems for bridges is shown. Benefits may be positive as well as negative from the user...... point of view. In the paper, negative benefits (user costs) are discussed in relation to the maintenance of concrete bridges. A limited number of excerpts from published reports that are related to the importance of estimating user costs when repairs of bridges are planned, and when optimized strategies......During the last two decades, important progress has been made in the life-cycle cost-benefit (LCCB) analysis of structures, especially offshore platforms, bridges and nuclear installations. Due to the large uncertainties related to the deterioration, maintenance, and benefits of such structures...

  15. Upgrade and optimization of control systems help E.ON's Scholven plant to increase plant lifecycle and meet new market requirements

    Alexander Frick; Joerg Orth

    2006-07-01

    A large percentage of Germany's installed base of power stations will continue to operate well into the next decade. E.ON therefore continues to focus on optimizing and maintaining its operating plants. A key component is the process control system - the data, information and nerve center of these plants. Parts shortages related to outdated technology and new, added process and operational requirements demand focused capital investment. E.ON has therefore implemented a program to upgrade a large part of the process control infrastructure at the Scholven facility. An important step was the successful replacement of the Unit C process control system during a ten-week maintenance outage in fall 2005. The new power station control system selected was ABB's System 800xA. 7 figs.

  16. A bridge network maintenance framework for Pareto optimization of stakeholders/users costs

    Orcesi, Andre D.; Cremona, Christian F.

    2010-01-01

    For managing highway bridges, stakeholders require efficient and practical decision making techniques. In a context of limited bridge management budget, it is crucial to determine the most effective breakdown of financial resources over the different structures of a bridge network. Bridge management systems (BMSs) have been developed for such a purpose. However, they generally rely on an individual approach. The influence of the position of bridges in the transportation network, the consequences of inadequate service for the network users, due to maintenance actions or bridge failure, are not taken into consideration. Therefore, maintenance strategies obtained with current BMSs do not necessarily lead to an optimal level of service (LOS) of the bridge network for the users of the transportation network. Besides, the assessment of the structural performance of highway bridges usually requires the access to the geometrical and mechanical properties of its components. Such information might not be available for all structures in a bridge network for which managers try to schedule and prioritize maintenance strategies. On the contrary, visual inspections are performed regularly and information is generally available for all structures of the bridge network. The objective of this paper is threefold (i) propose an advanced network-level bridge management system considering the position of each bridge in the transportation network, (ii) use information obtained at visual inspections to assess the performance of bridges, and (iii) compare optimal maintenance strategies, obtained with a genetic algorithm, when considering interests of users and bridge owner either separately as conflicting criteria, or simultaneously as a common interest for the whole community. In each case, safety and serviceability aspects are taken into account in the model when determining optimal strategies. The theoretical and numerical developments are applied on a French bridge network.

  17. Genetic algorithm trajectory plan optimization for EAMA: EAST Articulated Maintenance Arm

    Wu, Jing, E-mail: wujing@ipp.ac.cn [Institute of Plasma Physics, Chinese Academy of Sciences, 350 Shushanhu Rd., Hefei, Anhui (China); Lappeenranta University of Technology, Skinnarilankatu 34, Lappeenranta (Finland); Wu, Huapeng [Lappeenranta University of Technology, Skinnarilankatu 34, Lappeenranta (Finland); Song, Yuntao; Cheng, Yong; Zhao, Wenglong [Institute of Plasma Physics, Chinese Academy of Sciences, 350 Shushanhu Rd., Hefei, Anhui (China); Wang, Yongbo [Lappeenranta University of Technology, Skinnarilankatu 34, Lappeenranta (Finland)

    2016-11-01

    Highlights: • A redundant 10-DOF serial-articulated robot for EAST assembly and maintains is presented. • A trajectory optimization algorithm of the robot is developed. • A minimum jerk objective is presented to suppress machining vibration of the robot. - Abstract: EAMA (EAST Articulated Maintenance Arm) is an articulated serial manipulator with 7 degrees of freedom (DOF) articulated arm followed by 3-DOF gripper, total length is 8.867 m, works in experimental advanced superconductor tokamak (EAST) vacuum vessel (VV) to perform blanket inspection and remote maintenance tasks. This paper presents a trajectory optimization method which aims to pursue the 7-DOF articulated arm a stable movement, which keeps the mounted inspection camera anti-vibration. Based on dynamics analysis, trajectory optimization algorithm adopts multi-order polynomial interpolation in joint space and high order geometry Jacobian transform. The object of optimization algorithm is to suppress end-effector movement vibration by minimizing jerk RMS (root mean square) value. The proposed solution has such characteristics which can satisfy kinematic constraints of EAMA’s motion and ensure the arm running under the absolute values of velocity, acceleration and jerk boundaries. GA (genetic algorithm) is employed to find global and robust solution for this problem.

  18. Determining optimal preventive maintenance interval for component of Well Barrier Element in an Oil & Gas Company

    Siswanto, A.; Kurniati, N.

    2018-04-01

    An oil and gas company has 2,268 oil and gas wells. Well Barrier Element (WBE) is installed in a well to protect human, prevent asset damage and minimize harm to the environment. The primary WBE component is Surface Controlled Subsurface Safety Valve (SCSSV). The secondary WBE component is Christmas Tree Valves that consist of four valves i.e. Lower Master Valve (LMV), Upper Master Valve (UMV), Swab Valve (SV) and Wing Valve (WV). Current practice on WBE Preventive Maintenance (PM) program is conducted by considering the suggested schedule as stated on manual. Corrective Maintenance (CM) program is conducted when the component fails unexpectedly. Both PM and CM need cost and may cause production loss. This paper attempts to analyze the failure data and reliability based on historical data. Optimal PM interval is determined in order to minimize the total cost of maintenance per unit time. The optimal PM interval for SCSSV is 730 days, LMV is 985 days, UMV is 910 days, SV is 900 days and WV is 780 days. In average of all components, the cost reduction by implementing the suggested interval is 52%, while the reliability is improved by 4% and the availability is increased by 5%.

  19. Integrated approach to optimize operation and maintenance costs for operating nuclear power plants

    2006-06-01

    In the context of increasingly open electricity markets and the 'unbundling' of generating companies from former utility monopolies, an area of major concern is the economic performance of the existing fleet of nuclear power plants. Nuclear power, inevitably, must compete directly with other electricity generation sources. Coping with this competitive pressure is a challenge that the nuclear industry should meet if the nuclear option is to remain a viable one. This competitive environment has significant implications for nuclear plant operations, including, among others, the need for the more cost effective management of plant activities, and the greater use of analytical tools to balance the costs and benefits of proposed activities, in order to optimize operation and maintenance costs, and thus insure the economic competitiveness of existing nuclear power plants. In the framework of the activities on Nuclear Economic Performance Information System (NEPIS), the IAEA embarked in developing guidance on optimization of operation and maintenance costs for nuclear power plants. The report was prepared building on the fundamental that optimization of operation and maintenance costs of a nuclear power plant is a key component of a broader integrated business strategic planning process, having as overall result achievement of organization's business objectives. It provides advice on optimization of O and M costs in the framework of strategic business planning, with additional details on operational planning and controlling. This TECDOC was elaborated in 2004-2005 in the framework of the IAEA's programme on Nuclear Power Plant Operating Performance and Life Cycle Management, with the support of two consultants meetings and one technical meeting and based on contributions provided by participants. It can serve as a useful reference for the management and operation staff within utilities, nuclear power plant operators and regulators and other organizations involved in

  20. Optimal pricing policies for services with consideration of facility maintenance costs

    Yeh, Ruey Huei; Lin, Yi-Fang

    2012-06-01

    For survival and success, pricing is an essential issue for service firms. This article deals with the pricing strategies for services with substantial facility maintenance costs. For this purpose, a mathematical framework that incorporates service demand and facility deterioration is proposed to address the problem. The facility and customers constitute a service system driven by Poisson arrivals and exponential service times. A service demand with increasing price elasticity and a facility lifetime with strictly increasing failure rate are also adopted in modelling. By examining the bidirectional relationship between customer demand and facility deterioration in the profit model, the pricing policies of the service are investigated. Then analytical conditions of customer demand and facility lifetime are derived to achieve a unique optimal pricing policy. The comparative statics properties of the optimal policy are also explored. Finally, numerical examples are presented to illustrate the effects of parameter variations on the optimal pricing policy.

  1. A Decision Optimization Model for Leased Manufacturing Equipment with Warranty under Forecasting Production/Maintenance Problem

    Zied Hajej

    2015-01-01

    Full Text Available Due to the expensive production equipment, many manufacturers usually lease production equipment with a warranty period during a finite leasing horizon, rather than purchasing them. The lease contract contains the possibility of obtaining an extended warranty for a given additional cost. In this paper, based on the forecasting production/maintenance optimization problem, we develop a mathematical model to study the lease contract with basic and extended warranty based on win-win relationship between the lessee and the lessor. The influence of the production rates in the equipment degradation consequently on the total cost by each side during the finite leasing horizon is stated in order to determine a theoretical condition under which a compromise-pricing zone exists under different possibilities of maintenance policies.

  2. Optimal Maintenance Works for the Aborshada Road in the Western Region of Libya

    Youssef Medhat Abdelrahman

    2014-09-01

    Full Text Available In this research, the condition of a road pavement was investigated for the Aborshada Road in the Gharian region of Libya to determine the optimal maintenance works. Previously, a simple engineering judgment was the only procedure followed by the Gharian municipal engineers for evaluating pavements and prioritizing maintenance. The surface condition of the Aborshada Road pavement was investigated using “the Pavement Condition Index (PCI” visual technique. The pavement was inspected to survey the different distresses in each sample unit. Ninteen pavement distresses were classified according to the PCI standards (PCI for roads and parking lots became an ASTM standard in 2007 (D6433-07. It was necessary to know the most common distresses of the Aborshada Road to provide assistance for the decision maker in his evaluation of the pavement and the optimum repair method to be selected.

  3. Explicit formulas for the variance of discounted life-cycle cost

    Noortwijk, Jan M. van

    2003-01-01

    In life-cycle costing analyses, optimal design is usually achieved by minimising the expected value of the discounted costs. As well as the expected value, the corresponding variance may be useful for estimating, for example, the uncertainty bounds of the calculated discounted costs. However, general explicit formulas for calculating the variance of the discounted costs over an unbounded time horizon are not yet available. In this paper, explicit formulas for this variance are presented. They can be easily implemented in software to optimise structural design and maintenance management. The use of the mathematical results is illustrated with some examples

  4. Optimal preventive maintenance and repair policies for multi-state systems

    Sheu, Shey-Huei; Chang, Chin-Chih; Chen, Yen-Luan; George Zhang, Zhe

    2015-01-01

    This paper studies the optimal preventive maintenance (PM) policies for multi-state systems. The scheduled PMs can be either imperfect or perfect type. The improved effective age is utilized to model the effect of an imperfect PM. The system is considered as in a failure state (unacceptable state) once its performance level falls below a given customer demand level. If the system fails before a scheduled PM, it is repaired and becomes operational again. We consider three types of major, minimal, and imperfect repair actions, respectively. The deterioration of the system is assumed to follow a non-homogeneous continuous time Markov process (NHCTMP) with finite state space. A recursive approach is proposed to efficiently compute the time-dependent distribution of the multi-state system. For each repair type, we find the optimal PM schedule that minimizes the average cost rate. The main implication of our results is that in determining the optimal scheduled PM, choosing the right repair type will significantly improve the efficiency of the system maintenance. Thus PM and repair decisions must be made jointly to achieve the best performance

  5. Optimization of photovoltaic maintenance plan by means of a FMEA approach based on real data

    Villarini, Mauro; Cesarotti, Vittorio; Alfonsi, Lucrezia; Introna, Vito

    2017-01-01

    Highlights: • Application of RCM, based on FMEA, to photovoltaic systems. • MBS and FMEA determine RPN. • New maintenance plan aimed to reduce fixed RPN of criticalities. • Lower values of RPN by FMEA and major reliability of system obtained. - Abstract: There have been many scientific advances in the improvement of renewable energy systems. Recently, considerable interest has been given to their optimized management during their service life due to a large increase in the number of new renewable energy source power plants. High reliability levels are as important as high yields in order to maximize the useful green energy produced. Solar energy has been one of the most popular and exploited renewable sources in the market and therefore improvements in its efficiency and reliability have had a considerable impact. All energy systems require an increase in their conversion efficiency to reduce the consumption of primary energy. Moreover, the optimization of the performance of photovoltaic systems has increased their incidence as renewable sources in global power generation and has boosted their profitability. A failure of the components and sub-components of a working energy system cause two main issues; the first direct implication for the plant is the damage of the components and sub-components, and the second indirect implication is the consequent lack of energy production due to the plant being out of order. Furthermore, unforeseen failures of the components increase the uncontrollability of photovoltaic power systems, which worsens electric grid dispatching. The work presented here provides, for the first time, a complete and new assessment of Reliability Centered Maintenance carried out using a failure mode and effect analysis approach to photovoltaic systems. We use a large volume of data derived from a database of real maintenance activities carried out by a multinational company. These data were interpreted by the opinions of experts with specialist

  6. Satellite formation flying relative dynamics, formation design, fuel optimal maneuvers and formation maintenance

    Wang, Danwei; Poh, Eng Kee

    2017-01-01

    This book systematically describes the concepts and principles for multi-satellite relative motion, passive and near passive formation designs, trajectory planning and control for fuel optimal formation maneuvers, and formation flying maintenance control design. As such, it provides a sound foundation for researchers and engineers in this field to develop further theories and pursue their implementations. Though satellite formation flying is widely considered to be a major advance in space technology, there are few systematic treatments of the topic in the literature. Addressing that gap, the book offers a valuable resource for academics, researchers, postgraduate students and practitioners in the field of satellite science and engineering.

  7. Rules of Thumb in Life-Cycle Saving Decisions

    Winter, Joachim; Schlafmann, Kathrin; Rodepeter, Ralf

    2011-01-01

    We analyse life-cycle saving decisions when households use simple heuristics, or rules of thumb, rather than solve the underlying intertemporal optimization problem. We simulate life-cycle saving decisions using three simple rules and compute utility losses relative to the solution of the optimization problem. Our simulations suggest that utility losses induced by following simple decision rules are relatively low. Moreover, the two main saving motives re ected by the canonical life-cyc...

  8. Optimal condition-based maintenance decisions for systems with dependent stochastic degradation of components

    Hong, H.P.; Zhou, W.; Zhang, S.; Ye, W.

    2014-01-01

    Components in engineered systems are subjected to stochastic deterioration due to the operating environmental conditions, and the uncertainty in material properties. The components need to be inspected and possibly replaced based on preventive or failure replacement criteria to provide the intended and safe operation of the system. In the present study, we investigate the influence of dependent stochastic degradation of multiple components on the optimal maintenance decisions. We use copula to model the dependent stochastic degradation of components, and formulate the optimal decision problem based on the minimum expected cost rule and the stochastic dominance rules. The latter is used to cope with decision maker's risk attitude. We illustrate the developed probabilistic analysis approach and the influence of the dependency of the stochastic degradation on the preferred decisions through numerical examples

  9. Simultaneous and multi-criteria optimization of TS requirements and maintenance at NPPs

    Martorell, S.; Sanchez, A.; Carlos, S.; Serradell, V.

    2002-01-01

    One of the main concerns of the nuclear industry is to improve the availability of safety-related systems at nuclear power plants (NPPs) to achieve high safety levels. The development of efficient testing and maintenance has been traditionally one of the different ways to guarantee high levels of systems availability, which are implemented at NPP through technical specification and maintenance requirements (TS and M). On the other hand, there is a widely recognized interest in using the probabilistic risk analysis (PRA) for risk-informed applications aimed to emphasize both effective risk control and effective resource expenditures at NPPs. TS and M-related parameters in a plant are associated with controlling risk or with satisfying requirements, and are candidate to be evaluated for their resource effectiveness in risk-informed applications. The resource versus risk-control effectiveness principles formally enter in optimization problems where the cost or the burden for the plant staff is to be minimized while the risk or the availability of the safety equipment is constrained to be at a given level, and vice versa. Optimization of TS and M has been found interesting from the very beginning. However, the resolution of such a kind of optimization problem has been limited to focus on only individual TS and M-related parameters (STI, AOT, PM frequency, etc.) and/or adopting an individual optimization criterion (availability, costs, plant risks, etc.). Nevertheless, a number of reasons exist (e.g. interaction, similar scope, etc.) that justify the growing interest in the last years to focus on the simultaneous and multi-criteria optimization of TS and M. In the simultaneous optimization of TS and M-related parameters based on risk (or unavailability) and cost, like in many other engineering optimization problems, one normally faces multi-modal and non-linear objective functions and a variety of both linear and non-linear constraints. Genetic algorithms (GAs) have

  10. Safety constraints applied to an adaptive Bayesian condition-based maintenance optimization model

    Flage, Roger; Coit, David W.; Luxhøj, James T.; Aven, Terje

    2012-01-01

    A model is described that determines an optimal inspection and maintenance scheme for a deteriorating unit with a stochastic degradation process with independent and stationary increments and for which the parameters are uncertain. This model and resulting maintenance plans offers some distinct benefits compared to prior research because the uncertainty of the degradation process is accommodated by a Bayesian approach and two new safety constraints have been applied to the problem: (1) with a given subjective probability (degree of belief), the limiting relative frequency of one or more failures during a fixed time interval is bounded; or (2) the subjective probability of one or more failures during a fixed time interval is bounded. In the model, the parameter(s) of a condition-based inspection scheduling function and a preventive replacement threshold are jointly optimized upon each replacement and inspection such as to minimize the expected long run cost per unit of time, but also considering one of the specified safety constraints. A numerical example is included to illustrate the effect of imposing each of the two different safety constraints.

  11. Joint Optimization of Economic Production Quantity and Preventive Maintenance with Considering Multi-Products and Reserve Time

    Liu, Xuejuan; Wang, Binrong

    2017-01-01

    Purpose: We deal with the problem of the joint determination of optimal economic production quantity (EPQ) and optimal preventive maintenance (PM) for a system that can produce multiple products alternately. The objective is to find the optimal number of production cycles and the PM policy simultaneously by minimizing the cost model. Design/methodology/approach: Considering the products go through the system in a sequence and a complete run of all products forms a production cy...

  12. Extension of the maintenance cycle of HEPA filters by optimization of the technical characteristics of filters and their construction

    Bella, H.; Stiehl, H.H.; Sinhuber, D.

    1977-01-01

    The knowledge of the parameters of HEPA filters used at present in nuclear plants allows optimization of such filters with respect to flow rate, pressure drop and service life. The application of optimizing new types of HEPA filters of improved performance is reported. The calculated results were checked experimentally. The use of HEPA filters optimized with respect to dust capacity and service life, and the effects of this new type of filter on the reduction of operating and maintenance costs are discussed

  13. Product lifecycle management

    Stark, John

    2016-01-01

    This third edition updates and adds to the successful second edition and gives the reader a thorough description of PLM, providing them with a full understanding of the theory and the practical skills to implement PLM within their own business environment. This new and expanded edition is fully updated to reflect the many technological and management advances made in PLM since the release of the second edition. Describing the environment in which products are developed, manufactured and supported, before addressing the Five Pillars of PLM: business processes, product data, PLM applications, Organisational Change Management (OCM) and Project Management, this book explains what Product Lifecycle Management is, and why it’s needed. The final part of the book addresses the PLM timeline, showing the typical steps and activities of a PLM project or initiative. “Product Lifecycle Management” will broaden the reader’s understanding of PLM, nurturing the skills needed to implement PLM successfully and to achi...

  14. New technology for optimized I and C maintenance and management of ageing of critical equipment in nuclear power plants

    Hashemian, H.M.

    2000-01-01

    Advanced sensors and new testing and maintenance technologies have become available over the last ten years for nuclear power plants (NPPs) to replace outdated, obsolete, and troublesome instruments, provide for management of ageing of critical plant equipment, optimize maintenance activities, reduce maintenance costs and personnel radiation exposure, and at the same time, improve plant safety and availability. These new developments are reviewed in this TECDOC. The material covered here has been summarized from NUREG/CR-5501, a 1998 report written by H.M. Hashemian and his co-authors for the US Nuclear Regulatory Commission. (author)

  15. Joint redundancy and imperfect preventive maintenance optimization for series–parallel multi-state degraded systems

    Nourelfath, Mustapha; Châtelet, Eric; Nahas, Nabil

    2012-01-01

    This paper formulates a joint redundancy and imperfect preventive maintenance planning optimization model for series–parallel multi-state degraded systems. Non identical multi-state components can be used in parallel to improve the system availability by providing redundancy in subsystems. Multiple component choices are available in the market for each subsystem. The status of each component is considered to degrade with use. The objective is to determine jointly the maximal-availability series–parallel system structure and the appropriate preventive maintenance actions, subject to a budget constraint. System availability is defined as the ability to satisfy consumer demand that is represented as a piecewise cumulative load curve. A procedure is used, based on Markov processes and universal moment generating function, to evaluate the multi-state system availability and the cost function. A heuristic approach is also proposed to solve the formulated problem. This heuristic is based on a combination of space partitioning, genetic algorithms (GA) and tabu search (TS). After dividing the search space into a set of disjoint subsets, this approach uses GA to select the subspaces, and applies TS to each selected sub-space.

  16. OPTIMIZING MAINTENANCE PROCESSES ON CUSTOMER SITE IN A DECENTRALIZED ORGANIZATION BASED ON MULTI-SITE TEAMS

    Jorge Moutinho

    2015-03-01

    Full Text Available This lecture focuses on the complexity to manage and optimize maintenance processes, operations and service tasks to equipments and systems installed at customer sites. Different locations, access and working environment may compromise any standardization of setup's and operations. Multi-site teams based on geographic strategic locations, adds complexity to trainning, communication, supervising and monitoring processes. Logistics and information systems assume relevant rolls to consolidate global performance. Beside efficiency, effectiveness productivity and flexibility, field teams need skills on autonomy responsibility and proactivity. This lecture also explores the needed adaptation of most part of available literature, normally based on production sites, as also of Lean- Kaizen principles to the fact that services can not be stocked, quality is normally more difficult to measure and customer is normally present when and where service is produced.

  17. Hybrid Particle Swarm Optimization for Hybrid Flowshop Scheduling Problem with Maintenance Activities

    Li, Jun-qing; Pan, Quan-ke; Mao, Kun

    2014-01-01

    A hybrid algorithm which combines particle swarm optimization (PSO) and iterated local search (ILS) is proposed for solving the hybrid flowshop scheduling (HFS) problem with preventive maintenance (PM) activities. In the proposed algorithm, different crossover operators and mutation operators are investigated. In addition, an efficient multiple insert mutation operator is developed for enhancing the searching ability of the algorithm. Furthermore, an ILS-based local search procedure is embedded in the algorithm to improve the exploitation ability of the proposed algorithm. The detailed experimental parameter for the canonical PSO is tuning. The proposed algorithm is tested on the variation of 77 Carlier and Néron's benchmark problems. Detailed comparisons with the present efficient algorithms, including hGA, ILS, PSO, and IG, verify the efficiency and effectiveness of the proposed algorithm. PMID:24883414

  18. Hybrid Particle Swarm Optimization for Hybrid Flowshop Scheduling Problem with Maintenance Activities

    Jun-qing Li

    2014-01-01

    Full Text Available A hybrid algorithm which combines particle swarm optimization (PSO and iterated local search (ILS is proposed for solving the hybrid flowshop scheduling (HFS problem with preventive maintenance (PM activities. In the proposed algorithm, different crossover operators and mutation operators are investigated. In addition, an efficient multiple insert mutation operator is developed for enhancing the searching ability of the algorithm. Furthermore, an ILS-based local search procedure is embedded in the algorithm to improve the exploitation ability of the proposed algorithm. The detailed experimental parameter for the canonical PSO is tuning. The proposed algorithm is tested on the variation of 77 Carlier and Néron’s benchmark problems. Detailed comparisons with the present efficient algorithms, including hGA, ILS, PSO, and IG, verify the efficiency and effectiveness of the proposed algorithm.

  19. Hybrid particle swarm optimization for hybrid flowshop scheduling problem with maintenance activities.

    Li, Jun-qing; Pan, Quan-ke; Mao, Kun

    2014-01-01

    A hybrid algorithm which combines particle swarm optimization (PSO) and iterated local search (ILS) is proposed for solving the hybrid flowshop scheduling (HFS) problem with preventive maintenance (PM) activities. In the proposed algorithm, different crossover operators and mutation operators are investigated. In addition, an efficient multiple insert mutation operator is developed for enhancing the searching ability of the algorithm. Furthermore, an ILS-based local search procedure is embedded in the algorithm to improve the exploitation ability of the proposed algorithm. The detailed experimental parameter for the canonical PSO is tuning. The proposed algorithm is tested on the variation of 77 Carlier and Néron's benchmark problems. Detailed comparisons with the present efficient algorithms, including hGA, ILS, PSO, and IG, verify the efficiency and effectiveness of the proposed algorithm.

  20. Optimization of Reliability Centered Maintenance Bassed on Maintenance Costs and Reliability with Consideration of Location of Components

    Mahdi Karbasian

    2011-03-01

    Full Text Available The reliability of designing systems such as electrical and electronic circuits, power generation/ distribution networks and mechanical systems, in which the failure of a component may cause the whole system failure, and even the reliability of cellular manufacturing systems that their machines are connected to as series are critically important. So far approaches for improving the reliability of these systems have been mainly based on the enhancement of inherent reliability of any system component or increasing system reliability based on maintenance strategies. Also in some of the resources, only the influence of the location of systems' components on reliability is studied. Therefore, it seems other approaches have been rarely applied. In this paper, a multi criteria model has been proposed to perform a balance among a system's reliability, location costs, and its system maintenance. Finally, a numerical example has been presented and solved by the Lingo software.

  1. A holistic framework of degradation modeling for reliability analysis and maintenance optimization of nuclear safety systems

    Lin, Yanhui

    2016-01-01

    Components of nuclear safety systems are in general highly reliable, which leads to a difficulty in modeling their degradation and failure behaviors due to the limited amount of data available. Besides, the complexity of such modeling task is increased by the fact that these systems are often subject to multiple competing degradation processes and that these can be dependent under certain circumstances, and influenced by a number of external factors (e.g. temperature, stress, mechanical shocks, etc.). In this complicated problem setting, this PhD work aims to develop a holistic framework of models and computational methods for the reliability-based analysis and maintenance optimization of nuclear safety systems taking into account the available knowledge on the systems, degradation and failure behaviors, their dependencies, the external influencing factors and the associated uncertainties.The original scientific contributions of the work are: (1) For single components, we integrate random shocks into multi-state physics models for component reliability analysis, considering general dependencies between the degradation and two types of random shocks. (2) For multi-component systems (with a limited number of components):(a) a piecewise-deterministic Markov process modeling framework is developed to treat degradation dependency in a system whose degradation processes are modeled by physics-based models and multi-state models; (b) epistemic uncertainty due to incomplete or imprecise knowledge is considered and a finite-volume scheme is extended to assess the (fuzzy) system reliability; (c) the mean absolute deviation importance measures are extended for components with multiple dependent competing degradation processes and subject to maintenance; (d) the optimal maintenance policy considering epistemic uncertainty and degradation dependency is derived by combining finite-volume scheme, differential evolution and non-dominated sorting differential evolution; (e) the

  2. Infrastructures and Life-Cycle Cost-Benefit Analysis

    Thoft-Christensen, Palle

    2012-01-01

    Design and maintenance of infrastructures using Life-Cycle Cost-Benefit analysis is discussed in this paper with special emphasis on users costs. This is for several infrastructures such as bridges, highways etc. of great importance. Repair or/and failure of infrastructures will usually result...

  3. 10 CFR 455.64 - Life-cycle cost methodology.

    2010-01-01

    ...-investment ratio is the ratio of the present value of net cost savings attributable to an energy conservation measure to the present value of the net increase in investment, maintenance and operating, and replacement... present value. The format for displaying life-cycle costs shall be a savings-to-investment ratio. (b) An...

  4. Optimization of Two-Level Disassembly/Remanufacturing/Assembly System with an Integrated Maintenance Strategy

    Zouhour Guiras

    2018-04-01

    Full Text Available With an increase of environmental pressure on economic activities, reverse flow is increasingly important. It seeks to save resources, eliminate waste, and improve productivity. This paper investigates the optimization of the disassembly, remanufacturing and assembly system, taking into account assembly-disassembly system degradation. An analytical model is developed to consider disassembly, remanufacturing of used/end-of-life product and assembly of the finished product. The finished product is composed of remanufactured and new components. A maintenance policy is sequentially integrated to reduce the system unavailability. The aim of this study is to help decision-makers, under certain conditions, choose the most cost-effective process for them to satisfy the customer as well as to adapt to the potential risk that can perturb the disassembly-assembly system. A heuristic is developed to determine the optimal ordered date of the used end-of-life product as well as the optimum release dates of new external components. The results reveal that considering some remanufacturing and purchase components costs, the proposed model is more economical in comparison with a model without remanufactured parts. Numerical results are provided to illustrate the impact of the variation of the ordering cost and quality of the used end-of-life product on the system profitability. Finally, the risk due to system repair periods is discussed, which has an impact on managerial decision-making.

  5. On the optimal scheduling of periodic tests and maintenance for reliable redundant components

    Courtois, Pierre-Jacques; Delsarte, Philippe

    2006-01-01

    Periodically, some m of the n redundant components of a dependable system may have to be taken out of service for inspection, testing or preventive maintenance. The system is then constrained to operate with lower (n-m) redundancy and thus with less reliability during these periods. However, more frequent periodic inspections decrease the probability that a component fail undetected in the time interval between successive inspections. An optimal time schedule of periodic preventive operations arises from these two conflicting factors, balancing the loss of redundancy during inspections against the reliability benefits of more frequent inspections. Considering no other factor than this decreased redundancy at inspection time, this paper demonstrates the existence of an optimal interval between inspections, which maximizes the mean time between system failures. By suitable transformations and variable identifications, an analytic closed form expression of the optimum is obtained for the general (m, n) case. The optimum is shown to be unique within the ranges of parameter values valid in practice; its expression is easy to evaluate and shown to be useful to analyze and understand the influence of these parameters. Inspections are assumed to be perfect, i.e. they cause no component failure by themselves and leave no failure undetected. In this sense, the optimum determines a lowest bound for the system failure rate that can be achieved by a system of n-redundant components, m of which require for inspection or maintenance recurrent periods of unavailability of length t. The model and its general closed form solution are believed to be new . Previous work had computed optimal values for an estimation of a time average of system unavailability, but by numerical procedures only and with different numerical approximations, other objectives and model assumptions (one component only inspected at a time), and taking into account failures caused by testing itself, repair and

  6. New optimization strategies of pavement maintenance: A case study for national road network in Indonesia using integrated road management system

    Hamdi, Hadiwardoyo, Sigit P.; Correia, A. Gomes; Pereira, Paulo

    2017-06-01

    A road network requires timely maintenance to keep the road surface in good condition onward better services to improve accessibility and mobility. Strategies and maintenance techniques must be chosen in order to maximize road service level through cost-effective interventions. This approach requires an updated database, which the road network in Indonesia is supported by a manual and visual survey, also using NAASRA profiler. Furthermore, in this paper, the deterministic model of deterioration was used. This optimization model uses life cycle cost analysis (LCCA), applied in an integrated manner, using IRI indicator, and allows determining the priority of treatment, type of treatment and its relation to the cost. The purpose of this paper was focussed on the aspects of road maintenance management, i.e., maintenance optimization models for different levels of traffic and various initial of road distress conditions on the national road network in Indonesia. The implementation of Integrated Road Management System (IRMS) can provide a solution to the problem of cost constraints in the maintenance of the national road network. The results from this study found that as the lowest as agency cost, it will affect the increasing of user cost. With the achievement of the target plan scenario Pl000 with initial value IRI 2, it was found that the routine management throughout the year and in early reconstruction and periodic maintenance with a 30 mm thick overlay, will simultaneously provide a higher net benefit value and has the lowest total cost of transportation.

  7. A Proactive Aging/Asset Management Model to Optimize Equipment Maintenance Resources Over Plant Lifetime

    Meyer, Theodore A.; Perdue, Robert K.; Woodcock, Joel; Elder, G. Gary

    2002-01-01

    Experience has shown that proactive aging/asset management can best be defined as an ongoing process. Station goals directly supported by such a process include reducing Unplanned Capability Loss Factor and gaining the optimum value from maintenance and aging management budgets. An effective aging/asset management process must meet evolving and sometimes conflicting requirements for efficient and reliable nuclear power plant operation. The process should identify most likely contributors before they fail, and develop cost-effective contingencies. Current trends indicate the need for focused tools that give quantitative input to decision-making. Opposing goals, such as increasing availability while optimizing aging management budgets, must be balanced. Recognizing the importance of experience in reducing the uncertainty inherent in predicting equipment degradation rates, nuclear industry demographics suggest the need to capture existing expert knowledge in a usable form. The Proactive Aging/Asset Management Process has been developed to address these needs. The proactive approach is a process supported by tools. The process identifies goals and develops criteria - including safety, costs, and power production - that are used to prioritize systems and equipment across the plant. The process then draws upon tools to most effectively meet the plant's goals. The Proactive Aging/Asset Management Model TM is one software-enabled tool designed for mathematical optimization. Results assist a plant in developing a plant-wide plan of aging management activities. This paper describes the proactive aging/asset management process and provides an overview of the methodology that has been incorporated in a model to perform a plant-wide optimization of aging management activities. (authors)

  8. Preventive Maintenance Optimization in Healthcare Domain: Status of Research and Perspective

    Mahfoud, H.; El Barkany, A.; El Biyaali, A.

    2016-01-01

    Although medical equipment maintenance has been carefully managed for years, very few in-depth studies have been conducted to evaluate the effectiveness and efficiency of these implemented preventive maintenance strategies, especially after the debate about the credibility of manufacturer’s recommendations has increased in the clinical engineering community. Facing the dilemma of merely following manufactures maintenance manual or establishing an evidence-based maintenance, medical equipment ...

  9. Joint optimization of economic production quantity and preventive maintenance with considering multi-products and reserve time

    Liu, Xuejuan; Wang, Binrong

    2017-01-01

    Purpose: We deal with the problem of the joint determination of optimal economic production quantity (EPQ) and optimal preventive maintenance (PM) for a system that can produce multiple products alternately. The objective is to find the optimal number of production cycles and the PM policy simultaneously by minimizing the cost model. Design/methodology/approach: Considering the products go through the system in a sequence and a complete run of all products forms a production cycle. In each cycle, beyond production time we also consider some reserve time for maintenance and setup, shortage and overproduction may occur. We study the integrated problem based on two PM policies, and explain the situation with the other PM policies. The delay – time concept is used to model PM decisions. Findings: Using the integrated EPQ and PM model, we can calculate the optimal production planning and PM schedule simultaneously, especially we consider multiple products in each production cycle, which is more practical and economic than previous works. Originality/value: In modern companies, the production planning and maintenance schedule share the same system, and traditional research about two activities is separated, that always generate conflicts, such as inadequate or excessive maintenance, and shortages, etc., so we develop the integrated EPQ and PM model to avoid these undesirable effects.

  10. A New Biobjective Model to Optimize Integrated Redundancy Allocation and Reliability-Centered Maintenance Problems in a System Using Metaheuristics

    Shima MohammadZadeh Dogahe

    2015-01-01

    Full Text Available A novel integrated model is proposed to optimize the redundancy allocation problem (RAP and the reliability-centered maintenance (RCM simultaneously. A system of both repairable and nonrepairable components has been considered. In this system, electronic components are nonrepairable while mechanical components are mostly repairable. For nonrepairable components, a redundancy allocation problem is dealt with to determine optimal redundancy strategy and number of redundant components to be implemented in each subsystem. In addition, a maintenance scheduling problem is considered for repairable components in order to identify the best maintenance policy and optimize system reliability. Both active and cold standby redundancy strategies have been taken into account for electronic components. Also, net present value of the secondary cost including operational and maintenance costs has been calculated. The problem is formulated as a biobjective mathematical programming model aiming to reach a tradeoff between system reliability and cost. Three metaheuristic algorithms are employed to solve the proposed model: Nondominated Sorting Genetic Algorithm (NSGA-II, Multiobjective Particle Swarm Optimization (MOPSO, and Multiobjective Firefly Algorithm (MOFA. Several test problems are solved using the mentioned algorithms to test efficiency and effectiveness of the solution approaches and obtained results are analyzed.

  11. Joint optimization of economic production quantity and preventive maintenance with considering multi-products and reserve time

    Liu, Xuejuan; Wang, Binrong

    2017-07-01

    Purpose: We deal with the problem of the joint determination of optimal economic production quantity (EPQ) and optimal preventive maintenance (PM) for a system that can produce multiple products alternately. The objective is to find the optimal number of production cycles and the PM policy simultaneously by minimizing the cost model. Design/methodology/approach: Considering the products go through the system in a sequence and a complete run of all products forms a production cycle. In each cycle, beyond production time we also consider some reserve time for maintenance and setup, shortage and overproduction may occur. We study the integrated problem based on two PM policies, and explain the situation with the other PM policies. The delay – time concept is used to model PM decisions. Findings: Using the integrated EPQ and PM model, we can calculate the optimal production planning and PM schedule simultaneously, especially we consider multiple products in each production cycle, which is more practical and economic than previous works. Originality/value: In modern companies, the production planning and maintenance schedule share the same system, and traditional research about two activities is separated, that always generate conflicts, such as inadequate or excessive maintenance, and shortages, etc., so we develop the integrated EPQ and PM model to avoid these undesirable effects.

  12. Flat-plate photovoltaic array design optimization

    Ross, R. G., Jr.

    1980-01-01

    An analysis is presented which integrates the results of specific studies in the areas of photovoltaic structural design optimization, optimization of array series/parallel circuit design, thermal design optimization, and optimization of environmental protection features. The analysis is based on minimizing the total photovoltaic system life-cycle energy cost including repair and replacement of failed cells and modules. This approach is shown to be a useful technique for array optimization, particularly when time-dependent parameters such as array degradation and maintenance are involved.

  13. Optimization of radiation protection of cell maintenance of radiopharmaceutical production; Otimizacao da radioprotecao em manutencoes de celas de producao de radiofarmacos

    Machado, Jessica S.; Gerulis, Eduardo; Todo, Alberto S.; Rodrigues Junior, Orlando, E-mail: jsmachado@ipen.b, E-mail: egerulis@ipen.b, E-mail: astodo@ipen.b, E-mail: rodrijr@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), SP (Brazil)

    2011-10-26

    This paper performs a study of maintenance tasks realized in production cells to suggest improvements related to the occupational doses based on the optimization principle of the radioprotection. A data survey has been realized of the doses received by the workers during the maintenance. The average values of effective doses are lower than the limits established in the regulations, however can be optimized

  14. A new multi-objective optimization model for preventive maintenance and replacement scheduling of multi-component systems

    Moghaddam, Kamran S.; Usher, John S.

    2011-07-01

    In this article, a new multi-objective optimization model is developed to determine the optimal preventive maintenance and replacement schedules in a repairable and maintainable multi-component system. In this model, the planning horizon is divided into discrete and equally-sized periods in which three possible actions must be planned for each component, namely maintenance, replacement, or do nothing. The objective is to determine a plan of actions for each component in the system while minimizing the total cost and maximizing overall system reliability simultaneously over the planning horizon. Because of the complexity, combinatorial and highly nonlinear structure of the mathematical model, two metaheuristic solution methods, generational genetic algorithm, and a simulated annealing are applied to tackle the problem. The Pareto optimal solutions that provide good tradeoffs between the total cost and the overall reliability of the system can be obtained by the solution approach. Such a modeling approach should be useful for maintenance planners and engineers tasked with the problem of developing recommended maintenance plans for complex systems of components.

  15. New methods to minimize the preventive maintenance cost of series-parallel systems using ant colony optimization

    Samrout, M.; Yalaoui, F.; Cha-hat telet, E.; Chebbo, N.

    2005-01-01

    This article is based on a previous study made by Bris, Chatelet and Yalaoui [Bris R, Chatelet E, Yalaoui F. New method to minimise the preventive maintenance cost of series-parallel systems. Reliab Eng Syst Saf 2003;82:247-55]. They use genetic algorithm to minimize preventive maintenance cost problem for the series-parallel systems. We propose to improve their results developing a new method based on another technique, the Ant Colony Optimization (ACO). The resolution consists in determining the solution vector of system component inspection periods, T P . Those calculations were applied within the programming tool Matlab. Thus, highly interesting results and improvements of previous studies were obtained

  16. Optimization of calculation models of maintenance offers for new civil engines

    Pechoutre, Jean-Baptiste

    2011-01-01

    The sales support department performs calculations concerning maintenance offerings for civil engines based on the use of complex tools. This report describes the missions conducted during my Master's thesis: firstly, the establishment of a monitoring and security tool in the process of calculating maintenance costs. The second achievement is the creation of a tool for decision support in order to estimate and compare some of the maintenance costs associated with the use of the new commercial...

  17. The safety monitor and RCM workstation as complementary tools in risk based maintenance optimization

    Rawson, P.D.

    2000-01-01

    Reliability Centred Maintenance (RCM) represents a proven technique for rendering maintenance activities safer, more effective, and less expensive, in terms of systems unavailability and resource management. However, it is believed that RCM can be enhanced by the additional consideration of operational plant risk. This paper discusses how two computer-based tools, i.e., the RCM Workstation and the Safety Monitor, can complement each other in helping to create a living preventive maintenance strategy. (author)

  18. Operations and maintenance philosophy

    DUNCAN, G.P.

    1999-01-01

    This Operations and Maintenance (O and M) Philosophy document is intended to establish a future O and M vision, with an increased focus on minimizing worker exposure, ensuring uninterrupted retrieval operations, and minimizing operation life-cycle cost. It is intended that this document would incorporate O and M lessons learned into on-going and future project upgrades

  19. Monitoring Strategies in Permeable Pavement Systems to Optimize Maintenance Scheduling - abstract

    As the surface in a permeable pavement system clogs and performance decreases, maintenance is required to preserve the design function. Currently, guidance is limited for scheduling maintenance on an as needed basis. Previous research has shown that surface clogging in a permea...

  20. Optimization of the preventive maintenance plan of a series components system

    Duarte, Jose A. Caldeira [Mathematical Department, Instituto Politecnico de Setubal/Escola Superior de Tecnologia de Setubal, Campus do IPS, Estefanilha, 2914-508 Setubal (Portugal)]. E-mail: jduarte@est.ips.pt; Craveiro, Joao C. Taborda A. [MIIT, Manutencao Industrial Informatizada e Tecnologia, Lda, Av. Elias Garcia, 123, 5o, Lisbon (Portugal); Trigo, Tomas Pedro [MIIT, Manutencao Industrial Informatizada e Tecnologia, Lda, Av. Elias Garcia, 123, 5o, Lisbon (Portugal)

    2006-04-15

    One of the most critical problems in preventive maintenance is the determination of the optimum frequency to perform preventive maintenance in equipment, in order to ensure its availability. In this paper, we propose an algorithm to solve the previous problem for equipment that exhibit linearly increasing hazard rate and constant repair rate. Based on this algorithm, we have developed another one to solve the problem of maintenance management of a series system based on preventive maintenance over the different system components. We assume that all components of the system still exhibit linearly increasing hazard rate and constant repair rate and that preventive maintenance would bring the system to the as good as new condition. We define a cost function for maintenance tasks (preventive and corrective) for the system. The algorithm calculates the interval of time between preventive maintenance actions for each component, minimizing the costs, and in such a way that the total downtime, in a certain period of time, does not exceed a predetermined value.

  1. DEVELOPMENT OF MATHEMATICAL MODELS FOR OPTIMAL PREVENTIVE MAINTENANCE POLICY IN A STEEL INDUSTRY : SIX SIGMA APPROACH

    N. V. R. Naidu

    2011-09-01

    Full Text Available This paper deals with a critical evaluation of the Preventive Maintenance system in steel industry. This study helps in implementing Six Sigma solutions to reduce the down time of two critical machines i.e., Electric Arc Furnace (EAF and Billet Casting Machine (BCM. It is clear from the analysis of EAF and BCM respectively that, variations in output are quite possible because the machines output not only depend on maintenance time but also on several other variables. Further, the objective is to design a preventive maintenance programme on the same equipment situated in the plant using Six Sigma. The breakdown of these equipments could very well affect the production rate. For this, the mathematical models have been developed and these models are used to obtain the optimum preventive maintenance frequency for minimizing the down time and maximizing the profits.

  2. Uncertainties in the Forecasted Performance of Sediment Diversions Associated with Differences Between "Optimized" Diversion Design Criteria and the Natural Crevasse-Splay Sub-Delta Life-Cycle

    Brown, G.

    2017-12-01

    Sediment diversions have been proposed as a crucial component of the restoration of Coastal Louisiana. They are generally characterized as a means of creating land by mimicking natural crevasse-splay sub-delta processes. However, the criteria that are often promoted to optimize the performance of these diversions (i.e. large, sand-rich diversions into existing, degraded wetlands) are at odds with the natural processes that govern the development of crevasse-splay sub-deltas (typically sand-lean or sand-neutral diversions into open water). This is due in large part to the fact that these optimization criteria have been developed in the absence of consideration for the natural constraints associated with fundamental hydraulics: specifically, the conservation of mechanical energy. Although the implementation of the aforementioned optimization criteria have the potential to greatly increase the land-building capacity of a given diversion, the concomitant widespread inundation of the existing wetlands (an unavoidable consequence of diverting into a shallow, vegetated embayment), and the resultant stresses on existing wetland vegetation, have the potential to dramatically accelerate the loss of these existing wetlands. Hence, there are inherent uncertainties in the forecasted performance of sediment diversions that are designed according to the criteria mentioned above. This talk details the reasons for these uncertainties, using analytic and numerical model results, together with evidence from field observations and experiments. The likelihood that, in the foreseeable future, these uncertainties can be reduced, or even rationally bounded, is discussed.

  3. Maintenance Optimization Schedulingof Electric Power SystemsConsidering Renewable EnergySources

    Yu, Jia

    2015-01-01

    Maintenance is crucial in any industry to keep components in a reasonable functionalcondition, especially in electric power system, where maintenance is done so that thefrequency and the duration of a fault can be shortened, thus increasing the availability of acertain component. And the reliability of the whole electric power system can also beimproved. In the many deregulated electricity markets, reliability and economic drivingforces are the two aspects that system operators mainly conside...

  4. ANALYSIS OF GROUP MAINTENANCE STRATEGY -ROAD PAVEMENT AND SEWERAGE PIPES-

    Tanimoto, Keishi; Sugimoto, Yasuaki; Miyamoto, Shinya; Nada, Hideki; Hosoi, Yoshihiko

    Recently, it is critical to manage deteriorating sewerage and road facilities efficiently and strategically. Since the sewerage pipes are mostly installed under road pavement, the works for the replacement of the sewerage pipes are partially common to the works for the road. This means that the replacement cost can be saved by coordinating the timing of the replacements by sewerage pipe and road pavement. The purpose of the study is to develop the model based on Markov decision process to derive the optimal group maintenance policy so as to minimize lifecycle cost. Then the model is applied to case study area and demonstrated to estimate the lifecycle cost using statistical data such as pipe replacement cost, road pavement rehabilitation cost, and state of deterioration of pipes and road pavement.

  5. Radioactive materials transportation life-cycle cost

    Gregory, P.C.; Donovan, K.S.; Spooner, O.R.

    1993-01-01

    This paper discusses factors that should be considered when estimating the life-cycle cost of shipping radioactive materials and the development of a working model that has been successfully used. Today's environmental concerns have produced an increased emphasis on cleanup and restoration of production plants and interim storage sites for radioactive materials. The need to transport these radioactive materials to processing facilities or permanent repositories is offset by the reality of limited resources and ever-tightening budgets. Obtaining the true cost of transportation is often difficult because of the many direct and indirect costs involved and the variety of methods used to account for fixed and variable expenses. In order to make valid comparisons between the cost of alternate transportation systems for new and/or existing programs, one should consider more than just the cost of capital equipment or freight cost per mile. Of special interest is the cost of design, fabrication, use, and maintenance of shipping containers in accordance with the requirements of the U.S. Nuclear Regulatory Commission. A spread sheet model was developed to compare the life-cycle costs of alternate fleet configurations of TRUPACT-II, which will be used to ship transuranic waste from U.S. Department of Energy sites to the Waste Isolation Pilot Plant near Carlsbad, New Mexico

  6. [A Medical Devices Management Information System Supporting Full Life-Cycle Process Management].

    Tang, Guoping; Hu, Liang

    2015-07-01

    Medical equipments are essential supplies to carry out medical work. How to ensure the safety and reliability of the medical equipments in diagnosis, and reduce procurement and maintenance costs is a topic of concern to everyone. In this paper, product lifecycle management (PLM) and enterprise resource planning (ERP) are cited to establish a lifecycle management information system. Through integrative and analysis of the various stages of the relevant data in life-cycle, it can ensure safety and reliability of medical equipments in the operation and provide the convincing data for meticulous management.

  7. A multi-objective decision framework for lifecycle investment

    Timmermans, S.H.J.T.; Schumacher, J.M.; Ponds, E.H.M.

    2017-01-01

    In this paper we propose a multi-objective decision framework for lifecycle investment choice. Instead of optimizing individual strategies with respect to a single-valued objective, we suggest evaluation of classes of strategies in terms of the quality of the tradeoffs that they provide. The

  8. Premium cost optimization of operational and maintenance of green building in Indonesia using life cycle assessment method

    Latief, Yusuf; Berawi, Mohammed Ali; Basten, Van; Budiman, Rachmat; Riswanto

    2017-06-01

    Building has a big impact on the environmental developments. There are three general motives in building, namely the economy, society, and environment. Total completed building construction in Indonesia increased by 116% during 2009 to 2011. It made the energy consumption increased by 11% within the last three years. In fact, 70% of energy consumption is used for electricity needs on commercial buildings which leads to an increase of greenhouse gas emissions by 25%. Green Building cycle costs is known as highly building upfront cost in Indonesia. The purpose of optimization in this research improves building performance with some of green concept alternatives. Research methodology is mixed method of qualitative and quantitative approaches through questionnaire surveys and case study. Assessing the successful of optimization functions in the existing green building is based on the operational and maintenance phase with the Life Cycle Assessment Method. Choosing optimization results were based on the largest efficiency of building life cycle and the most effective cost to refund.

  9. Development of stand-alone risk assessment software for optimized maintenance planning of power plant facilities

    Choi, Woo Sung; Song, Gee Wook; Kim, Bum Shin; Chang, Sung Ho; Lee, Sang Min

    2015-01-01

    Risk-Risk-based inspection (RBI) has been developed in order to identify risky equipment that can cause major accidents or damages in large-scale plants. This assessment evaluates the equipment's risk, categorizes their priorities based on risk level, and then determines the urgency of their maintenance or allocates maintenance resources. An earlier version of the risk-based assessment software is already installed within the equipment management system; however, the assessment is based on examination by an inspector, and the results can be influenced by his subjective judgment, rather than assessment being based on failure probability. Moreover, the system is housed within a server, which limits the inspector's work space and time, and such a system can be used only on site. In this paper, the development of independent risk-based assessment software is introduced; this software calculates the failure probability by an analytical method, and analyzes the field inspection results, as well as inspection effectiveness. It can also operate on site, since it can be installed on an independent platform, and has the ability to generate an I/O function for the field inspection results regarding the period for an optimum maintenance cycle. This program will provide useful information not only to the field users who are participating in maintenance, but also to the engineers who need to decide whether to extend the life cycle of the power machinery or replace only specific components

  10. A Novel Idea for Optimizing Condition-Based Maintenance Using Genetic Algorithms and Continuous Event Simulation Techniques

    Mansoor Ahmed Siddiqui

    2017-01-01

    Full Text Available Effective maintenance strategies are of utmost significance for system engineering due to their direct linkage with financial aspects and safety of the plants’ operation. At a point where the state of a system, for instance, level of its deterioration, can be constantly observed, a strategy based on condition-based maintenance (CBM may be affected; wherein upkeep of the system is done progressively on the premise of monitored state of the system. In this article, a multicomponent framework is considered that is continuously kept under observation. In order to decide an optimal deterioration stage for the said system, Genetic Algorithm (GA technique has been utilized that figures out when its preventive maintenance should be carried out. The system is configured into a multiobjective problem that is aimed at optimizing the two desired objectives, namely, profitability and accessibility. For the sake of reality, a prognostic model portraying the advancements of deteriorating system has been employed that will be based on utilization of continuous event simulation techniques. In this regard, Monte Carlo (MC simulation has been shortlisted as it can take into account a wide range of probable options that can help in reducing uncertainty. The inherent benefits proffered by the said simulation technique are fully utilized to display various elements of a deteriorating system working under stressed environment. The proposed synergic model (GA and MC is considered to be more effective due to the employment of “drop-by-drop approach” that permits successful drive of the related search process with regard to the best optimal solutions.

  11. The DCC Curation Lifecycle Model

    Sarah Higgins

    2008-08-01

    Full Text Available Lifecycle management of digital materials is necessary to ensure their continuity. The DCC Curation Lifecycle Model has been developed as a generic, curation-specific, tool which can be used, in conjunction with relevant standards, to plan curation and preservation activities to different levels of granularity. The DCC will use the model: as a training tool for data creators, data curators and data users; to organise and plan their resources; and to help organisations identify risks to their digital assets and plan management strategies for their successful curation.

  12. Introduction to the ITIL service lifecycle

    , AXELOS

    2012-01-01

    Introduction to the ITIL Service Lifecycle' introduces IT service management and ITIL. It summarises the best practices described in the 2011 editions' core guidance, explaining the basic concepts of ITIL and providing information on each stage of the service lifecycle.

  13. Life-cycle Energy and Emissions Inventories for Motorcycles, Diesel Automobiles, School Buses, Electric Buses, Chicago Rail, and New York City Rail

    Chester, Mikhail; Horvath, Arpad

    2009-01-01

    The development of life-cycle energy and emissions factors for passenger transportation modes is critical for understanding the total environmental costs of travel. Previous life-cycle studies have focused on the automobile given its dominating share of passenger travel and have included only few life-cycle components, typically related to the vehicle (i.e., manufacturing, maintenance, end-of-life) or fuel (i.e., extraction, refining, transport). Chester (2009) provides the first comprehensiv...

  14. Design Buildings Optimally: A Lifecycle Assessment Approach

    Hosny, Ossama; Elhakeem, Ahmed

    2013-01-01

    Cycle Cost (LCC). It consists of three main modules: (1) a custom Building InformationModel (BIM) for desert buildings with a compatibility checker as a central interactive database; (2) a system evaluator module to evaluate the proposed success measures

  15. Evaluation of life-cycle air emission factors of freight transportation.

    Facanha, Cristiano; Horvath, Arpad

    2007-10-15

    Life-cycle air emission factors associated with road, rail, and air transportation of freight in the United States are analyzed. All life-cycle phases of vehicles, infrastructure, and fuels are accounted for in a hybrid life-cycle assessment (LCA). It includes not only fuel combustion, but also emissions from vehicle manufacturing, maintenance, and end of life, infrastructure construction, operation, maintenance, and end of life, and petroleum exploration, refining, and fuel distribution. Results indicate that total life-cycle emissions of freight transportation modes are underestimated if only tailpipe emissions are accounted for. In the case of CO2 and NOx, tailpipe emissions underestimate total emissions by up to 38%, depending on the mode. Total life-cycle emissions of CO and SO2 are up to seven times higher than tailpipe emissions. Sensitivity analysis considers the effects of vehicle type, geography, and mode efficiency on the final results. Policy implications of this analysis are also discussed. For example, while it is widely assumed that currently proposed regulations will result in substantial reductions in emissions, we find that this is true for NOx, emissions, because fuel combustion is the main cause, and to a lesser extent for SO2, but not for PM10 emissions, which are significantly affected by the other life-cycle phases.

  16. Optimized protocols for Mycobacterium leprae strain management: frozen stock preservation and maintenance in athymic nude mice.

    Trombone, Ana Paula Fávaro; Pedrini, Sílvia Cristina Barbosa; Diório, Suzana Madeira; Belone, Andréa de Faria Fernandes; Fachin, Luciana Raquel Vicenzi; do Nascimento, Dejair Caitano; Rosa, Patricia Sammarco

    2014-03-23

    Leprosy, caused by Mycobacterium leprae, is an important infectious disease that is still endemic in many countries around the world, including Brazil. There are currently no known methods for growing M. leprae in vitro, presenting a major obstacle in the study of this pathogen in the laboratory. Therefore, the maintenance and growth of M. leprae strains are preferably performed in athymic nude mice (NU-Foxn1(nu)). The laboratory conditions for using mice are readily available, easy to perform, and allow standardization and development of protocols for achieving reproducible results. In the present report, we describe a simple protocol for purification of bacilli from nude mouse footpads using trypsin, which yields a suspension with minimum cell debris and with high bacterial viability index, as determined by fluorescent microscopy. A modification to the standard method for bacillary counting by Ziehl-Neelsen staining and light microscopy is also demonstrated. Additionally, we describe a protocol for freezing and thawing bacillary stocks as an alternative protocol for maintenance and storage of M. leprae strains.

  17. Multicriterial optimization of preventive maintenance of informational/technical stochastic system

    Kovalenko Anna

    2016-01-01

    Full Text Available The problem of optimization of reliability and economical indexes is solved for informational/technical system with periodical diagnostics and restoration. The system considered is the one with users accesses and errors occurring. The probability that the error occurs increases in time. Therefore, the longer is the restoration period the more there is a risk of system operation with error. But too frequent restoration can be too expensive. To take into account all these factors two-criteria optimization is made with the restriction of reliability characteristic being of the given level.

  18. Implementing risk-informed life-cycle design

    Hill, Ralph S. III

    2007-01-01

    This paper describes a design process based on risk-informed probabilistic methodologies that cover a facility's life-cycle from start of conceptual design through decontamination and decommissioning. The concept uses probabilistic risk assessments to identify target reliabilities for facility systems and components. Target reliabilities are used in system and subsystem simulation analyses to determine the optimum combination of initial system and component construction reliability, maintenance frequency, and inspection frequency for both active and passive components. The target reliabilities are also used for system based code margin exchange to reduce excessive level of margins to appropriate levels resulting in a more flexible structure of codes and standards that improves facility reliability and cost. The paper includes a description of a risk informed life-cycle design process, a summary of work being done, and a discussion of work needed to implement the process. (author)

  19. Neuroimaging markers associated with maintenance of optimal memory performance in late-life.

    Dekhtyar, Maria; Papp, Kathryn V; Buckley, Rachel; Jacobs, Heidi I L; Schultz, Aaron P; Johnson, Keith A; Sperling, Reisa A; Rentz, Dorene M

    2017-06-01

    Age-related memory decline has been well-documented; however, some individuals reach their 8th-10th decade while maintaining strong memory performance. To determine which demographic and biomarker factors differentiated top memory performers (aged 75+, top 20% for memory) from their peers and whether top memory performance was maintained over 3 years. Clinically normal adults (n=125, CDR=0; age: 79.5±3.57 years) from the Harvard Aging Brain Study underwent cognitive testing and neuroimaging (amyloid PET, MRI) at baseline and 3-year follow-up. Participants were grouped into Optimal (n=25) vs. Typical (n=100) performers using performance on 3 challenging memory measures. Non-parametric tests were used to compare groups. There were no differences in age, sex, or education between Optimal vs. Typical performers. The Optimal group performed better in Processing Speed (p=0.016) and Executive Functioning (pmemory performance while 7 declined. Non-Maintainers additionally declined in Executive Functioning but not Processing Speed. Longitudinally, there were no hippocampal volume differences between Maintainers and Non-Maintainers, however Non-Maintainers exhibited higher amyloid burden at baseline in contrast with Maintainers (p=0.008). Excellent memory performance in late life does not guarantee protection against cognitive decline. Those who maintain an optimal memory into the 8th and 9th decades may have lower levels of AD pathology. Copyright © 2017. Published by Elsevier Ltd.

  20. Availability analysis of mechanical systems with condition-based maintenance using semi-Markov and evaluation of optimal condition monitoring interval

    Kumar, Girish; Jain, Vipul; Gandhi, O. P.

    2018-03-01

    Maintenance helps to extend equipment life by improving its condition and avoiding catastrophic failures. Appropriate model or mechanism is, thus, needed to quantify system availability vis-a-vis a given maintenance strategy, which will assist in decision-making for optimal utilization of maintenance resources. This paper deals with semi-Markov process (SMP) modeling for steady state availability analysis of mechanical systems that follow condition-based maintenance (CBM) and evaluation of optimal condition monitoring interval. The developed SMP model is solved using two-stage analytical approach for steady-state availability analysis of the system. Also, CBM interval is decided for maximizing system availability using Genetic Algorithm approach. The main contribution of the paper is in the form of a predictive tool for system availability that will help in deciding the optimum CBM policy. The proposed methodology is demonstrated for a centrifugal pump.

  1. Video-on-demand network design and maintenance using fuzzy optimization.

    Abadpour, Arash; Alfa, Attahiru Sule; Diamond, Jeff

    2008-04-01

    Video-on-demand (VoD) is the entertainment source that, in the future, will likely overtake regular television in many aspects. Although many companies have deployed working VoD services, some aspects of the VoD should still undergo further improvement in order for it to reach to the foreseen potentials. An important aspect of a VoD system is the underlying network in which it operates. According to the huge number of customers in this network, it should be carefully designed to fulfill certain performance criteria. This process should be capable of finding optimal locations for the nodes of the network as well as determining the content that should be cached in each one. While this problem is categorized in the general group of network optimization problems, its specific characteristics demand a new solution to be sought for it. In this paper, which is inspired by the successful use of fuzzy optimization in similar problems in other fields, a fuzzy objective function that is heuristically shown to minimize the communication cost in a VoD network is derived while also controlling the storage cost. Then, an iterative algorithm is proposed to find a locally optimal solution to the proposed objective function. Capitalizing on the unrepeatable tendency of the proposed algorithm, a heuristic method for picking a good solution from a bundle of solutions produced by the proposed algorithm is also suggested. This paper includes a formal statement of the problem and its mathematical analysis. In addition, different scenarios in which the proposed algorithm can be utilized are discussed.

  2. General Concerns Life-Cycle Design of Economical Ice-Resistant Structures in the Bohai Sea

    Zhang Da-yong

    2017-08-01

    Full Text Available In China, the oil and natural gas resources of Bohai Bay are mainly marginal oil fields. It is necessary to build both iceresistant and economical offshore platforms. However, there are many risks during the life cycle of offshore platforms due to the imperfect preliminary design for the Bohai Sea economical ice-resistant structures. As a result, the whole life-cycle design should be considered, including plan, design, construction, management and maintenance design. Based on the demand of existing codes and research of the basic design, structural ice-resistant performance and the reasonable management and maintenance, the life-cycle design theory is discussed. It was concluded that the life-cycle cost-effective optimum design proposed will lead to a minimum risk.

  3. Optimization of preventive maintenance cycle based on experimental feedback in nuclear power plants

    Shi Jie

    2010-01-01

    The preventive replacement method based on the experimental feedback was introduced. In this method, the initial preventive replacement cycle was acquired by expert votes. The preventive replacement cycle combined with the operation experience of the equipment was gained by means of Bayesian theorem. The Optimized preventive replacement cycle can be acquired by comparing the two probabilities that no fault occurs within the cycle. This method was tested on the switches which were used in Daya Bay Nuclear Power Plant and the results indicated its validity. (authors)

  4. Ex Vivo Maintenance of Primary Human Multiple Myeloma Cells through the Optimization of the Osteoblastic Niche.

    Zhang, Wenting; Gu, Yexin; Sun, Qiaoling; Siegel, David S; Tolias, Peter; Yang, Zheng; Lee, Woo Y; Zilberberg, Jenny

    2015-01-01

    We previously reported a new approach for culturing difficult-to-preserve primary patient-derived multiple myeloma cells (MMC) using an osteoblast (OSB)-derived 3D tissue scaffold constructed in a perfused microfluidic environment and a culture medium supplemented with patient plasma. In the current study, we used this biomimetic model to show, for the first time, that the long-term survival of OSB is the most critical factor in maintaining the ex vivo viability and proliferative capacity of MMC. We found that the adhesion and retention of MMC to the tissue scaffold was meditated by osteoblastic N-cadherin, as one of potential mechanisms that regulate MMC-OSB interactions. However, in the presence of MMC and patient plasma, the viability and osteogenic activity of OSB became gradually compromised, and consequently MMC could not remain viable over 3 weeks. We demonstrated that the long-term survival of both OSB and MMC could be enhanced by: (1) optimizing perfusion flow rate and patient-derived plasma composition in the culture medium and (2) replenishing OSB during culture as a practical means of prolonging MMC's viability beyond several weeks. These findings were obtained using a high-throughput well plate-based perfusion device from the perspective of optimizing the ex vivo preservation of patient-derived MM biospecimens for downstream use in biological studies and chemosensitivity analyses.

  5. Ex Vivo Maintenance of Primary Human Multiple Myeloma Cells through the Optimization of the Osteoblastic Niche.

    Wenting Zhang

    Full Text Available We previously reported a new approach for culturing difficult-to-preserve primary patient-derived multiple myeloma cells (MMC using an osteoblast (OSB-derived 3D tissue scaffold constructed in a perfused microfluidic environment and a culture medium supplemented with patient plasma. In the current study, we used this biomimetic model to show, for the first time, that the long-term survival of OSB is the most critical factor in maintaining the ex vivo viability and proliferative capacity of MMC. We found that the adhesion and retention of MMC to the tissue scaffold was meditated by osteoblastic N-cadherin, as one of potential mechanisms that regulate MMC-OSB interactions. However, in the presence of MMC and patient plasma, the viability and osteogenic activity of OSB became gradually compromised, and consequently MMC could not remain viable over 3 weeks. We demonstrated that the long-term survival of both OSB and MMC could be enhanced by: (1 optimizing perfusion flow rate and patient-derived plasma composition in the culture medium and (2 replenishing OSB during culture as a practical means of prolonging MMC's viability beyond several weeks. These findings were obtained using a high-throughput well plate-based perfusion device from the perspective of optimizing the ex vivo preservation of patient-derived MM biospecimens for downstream use in biological studies and chemosensitivity analyses.

  6. Default, Framing and Spillover Effects: The Case of Lifecycle Funds in 401(k) Plans

    Olivia S. Mitchell; Gary R. Mottola; Stephen P. Utkus; Takeshi Yamaguchi

    2009-01-01

    Important behavioral factors such as default and framing effects are increasingly being employed to optimize decision-making in a variety of settings, including individually-directed retirement plans. Yet such approaches may have unintended "spillover" effects, as we show with regard to the introduction of lifecycle funds in U.S. 401(k) plans. As anticipated, lifecycle funds do reshape individual portfolio choices through large default and framing effects. But unexpectedly, they also create a...

  7. Rules of thumb in life-cycle savings models

    Rodepeter, Ralf; Winter, Joachim

    1999-01-01

    We analyze life-cycle savings decisions when households use simple heuristics, or rules of thumb, rather than solve the underlying intertemporal optimization problem. The decision rules we explore are a simple Keynesian rule where consumption follows income; a simple consumption rule where only a fraction of positive income shocks is saved; a rule that corresponds to the permanent income hypothesis; and two rules that have been found in experimental studies. Using these rules, we simulate lif...

  8. Technology development of maintenance optimization and reliability analysis for safety features in nuclear power plants

    Kim, Tae Woon; Choi, Seong Soo; Lee, Dong Gue; Kim, Young Il

    1999-12-01

    The reliability data management system (RDMS) for safety systems of PHWR type plants has been developed and utilized in the reliability analysis of the special safety systems of Wolsong Unit 1,2 with plant overhaul period lengthened. The RDMS is developed for the periodic efficient reliability analysis of the safety systems of Wolsong Unit 1,2. In addition, this system provides the function of analyzing the effects on safety system unavailability if the test period of a test procedure changes as well as the function of optimizing the test periods of safety-related test procedures. The RDMS can be utilized in handling the requests of the regulatory institute actively with regard to the reliability validation of safety systems. (author)

  9. The Data Warehouse Lifecycle Toolkit

    Kimball, Ralph; Thornthwaite, Warren; Mundy, Joy; Becker, Bob

    2011-01-01

    A thorough update to the industry standard for designing, developing, and deploying data warehouse and business intelligence systemsThe world of data warehousing has changed remarkably since the first edition of The Data Warehouse Lifecycle Toolkit was published in 1998. In that time, the data warehouse industry has reached full maturity and acceptance, hardware and software have made staggering advances, and the techniques promoted in the premiere edition of this book have been adopted by nearly all data warehouse vendors and practitioners. In addition, the term "business intelligence" emerge

  10. Development Of An Optimal Planning And Maintenance System A Case Study Of Shell Petroleum Development Company Obigbo Node

    Temple Temple Amachree

    2017-08-01

    Full Text Available Preventive and breakdown maintenance system for a gas compressor plant were analyzed and appraised using established maintenance tools. To determine this comparative cost benefit analysis of preventive and breakdown maintenance activities on Agbada gas compressor plant of the Shell Petroleum Development Company was carried out. The cost of achieving 20000 run hours overhaul preventive maintenance with some disused repaired parts was analyzed and compared with the cost of carrying out the same activity with all new parts. Comparative studies showed that carrying out preventive maintenance with repairable parts which were recovered in the as new state is more cost effective than using all new parts. A cost saving of 14.63 was achieved. The same trend was also observed when the cost benefit analysis was carried out in breakdown maintenance option. This again gave a cost savings of 7.51 when repaired disused parts were used. The results showed that the rate of return on investment if breakdown maintenance is adopted is 24 as compared to the rate of return 01 26 that was obtained when preventive maintenance system was used. An NPV of N6703491725.00 and N5371346424.00 were obtained for preventive maintenance and breakdown maintenance respectively. It is therefore observed that preventive maintenance system strategy presented a better NPV over breakdown maintenance.

  11. A comparative study on using meta-heuristic algorithms for road maintenance planning: Insights from field study in a developing country

    Ali Gerami Matin

    2017-10-01

    Full Text Available Optimized road maintenance planning seeks for solutions that can minimize the life-cycle cost of a road network and concurrently maximize pavement condition. Aiming at proposing an optimal set of road maintenance solutions, robust meta-heuristic algorithms are used in research. Two main optimization techniques are applied including single-objective and multi-objective optimization. Genetic algorithms (GA, particle swarm optimization (PSO, and combination of genetic algorithm and particle swarm optimization (GAPSO as single-objective techniques are used, while the non-domination sorting genetic algorithm II (NSGAII and multi-objective particle swarm optimization (MOPSO which are sufficient for solving computationally complex large-size optimization problems as multi-objective techniques are applied and compared. A real case study from the rural transportation network of Iran is employed to illustrate the sufficiency of the optimum algorithm. The formulation of the optimization model is carried out in such a way that a cost-effective maintenance strategy is reached by preserving the performance level of the road network at a desirable level. So, the objective functions are pavement performance maximization and maintenance cost minimization. It is concluded that multi-objective algorithms including non-domination sorting genetic algorithm II (NSGAII and multi-objective particle swarm optimization performed better than the single objective algorithms due to the capability to balance between both objectives. And between multi-objective algorithms the NSGAII provides the optimum solution for the road maintenance planning.

  12. Assessing maintenance contracts when preventive maintenance is outsourced

    Wu Shaomin

    2012-01-01

    In some companies, corrective maintenance is conducted in-house but preventive maintenance might be outsourced. This raises a need to optimise some parameters such as the number of contracts from a perspective of the equipment owner. This paper considers a maintenance policy for such a situation, analyses the roles of the parameters in a PM model, proposes approaches to defining bonus functions, and finally discusses special cases of both the PM policy and the bonus function. Numerical examples are also given to explore the impact of parameters on the expected lifecycle cost rate.

  13. Reliability Analysis and Optimal Release Problem Considering Maintenance Time of Software Components for an Embedded OSS Porting Phase

    Tamura, Yoshinobu; Yamada, Shigeru

    OSS (open source software) systems which serve as key components of critical infrastructures in our social life are still ever-expanding now. Especially, embedded OSS systems have been gaining a lot of attention in the embedded system area, i.e., Android, BusyBox, TRON, etc. However, the poor handling of quality problem and customer support prohibit the progress of embedded OSS. Also, it is difficult for developers to assess the reliability and portability of embedded OSS on a single-board computer. In this paper, we propose a method of software reliability assessment based on flexible hazard rates for the embedded OSS. Also, we analyze actual data of software failure-occurrence time-intervals to show numerical examples of software reliability assessment for the embedded OSS. Moreover, we compare the proposed hazard rate model for the embedded OSS with the typical conventional hazard rate models by using the comparison criteria of goodness-of-fit. Furthermore, we discuss the optimal software release problem for the porting-phase based on the total expected software maintenance cost.

  14. SURVEY REGARDING THE LEVEL OF PRODUCT LIFECYCLE MANAGEMENT IN MANUFACTURING COMPANIES

    František Freiberg

    2011-12-01

    Full Text Available This article is about a questionnaire survey regarding the level of product lifecycle management in manufacturing companies in the Czech Republic. Based on the research available from foreign and domestic literature, a questionnaire survey was compiled and carried out with the purpose of applying the methods used in the life cycle management in selected areas: maintenance, information systems and the cost of the product lifecycle. The survey is carried out through a printed as well as an electronic questionnaire with additional structured interviews in selected manufacturing companies in the Czech Republic, Slovak Republic and Romania.

  15. Reducing costs with optimized maintenance strategies. Energie AG Oberoesterreich's practical experience with computer-aided maintenance planning and order processing; Kostensenkung durch optimale Instandhaltungsstrategien. Einsatzerfahrungen der Energie AG Oberoesterreich mit EDV-gestuetzter IH-Planung und Auftragsabwicklung

    Lechner, K.D.; Raffelsberger, K.; Steininger, W. [Energie AG Oberoesterreich (Austria); Roeben, U. [Siemens Power Generation AG, Erlangen (Germany)

    2004-07-01

    With the increasing competition, application of the optimal maintenance strategy is gaining importance. Apart from optimizing direct maintenance costs, the effects on profit (e.g. due to loss of production), follow-up costs in plant operation as well as safety-related aspects and the environmental impact are important factors. Without state-of-the-art plant management and maintenance software, efficiently meeting the resulting requirements is quite impossible. (orig.)

  16. Virtual and augmented reality in the nuclear plant lifecycle perspective

    Johnsen, Terje; Mark, Niels-Kristian

    2010-01-01

    The paper presents a subset of the research and development performed over the last decade by the OECD Halden Reactor Project (HRP) using virtual reality (VR) and augmented reality (AR) in design, operation, maintenance and decommissioning to solve real world problems in the nuclear plant lifecycle. The use of VR in training at Leningrad Nuclear Power Plant (LNPP) in Russia started in 1999 with the introduction of VR technology developed by Institute for Energy Technology (IFE) for the training and presentation of procedures related to safe operation and maintenance of the refuelling machine. At Chernobyl Nuclear Power Plant (ChNPP) in Ukraine, the establishment of the Chernobyl Decommissioning Visualisation Centre (CDVC) was started in 2007. The CDVC will be used for planning, training and presentation of dismantling procedures. In the future, the CDVC will also offer calculation of the occupational dose. VR has proven to be an effective technology for better communicating the layout of project proposals in design of control rooms. AR can be used to supplement reality by blending the physical and the virtual in the actual physical environment. IFE has developed a practical solution for using the AR technology. The paper also discusses how and for what areas the VR and AR applications can contribute to the nuclear safety for symbiosis and sustainability. Finally, IFE's plans for future use of VR and AR technologies in a nuclear plant lifecycle perspective are discussed. (author)

  17. Optimal Medical Equipment Maintenance Service Proposal Decision Support System combining Activity Based Costing (ABC) and the Analytic Hierarchy Process (AHP).

    da Rocha, Leticia; Sloane, Elliot; M Bassani, Jose

    2005-01-01

    This study describes a framework to support the choice of the maintenance service (in-house or third party contract) for each category of medical equipment based on: a) the real medical equipment maintenance management system currently used by the biomedical engineering group of the public health system of the Universidade Estadual de Campinas located in Brazil to control the medical equipment maintenance service, b) the Activity Based Costing (ABC) method, and c) the Analytic Hierarchy Process (AHP) method. Results show the cost and performance related to each type of maintenance service. Decision-makers can use these results to evaluate possible strategies for the categories of equipment.

  18. Joint optimization of economic production quantity and preventive maintenance with considering multi-products and reserve time

    Xuejuan Liu

    2017-07-01

    Originality/value: In modern companies, the production planning and maintenance schedule share the same system, and traditional research about two activities is separated, that always generate conflicts, such as inadequate or excessive maintenance, and shortages, etc., so we develop the integrated EPQ and PM model to avoid these undesirable effects.

  19. Lifecycle management for nuclear engineering project documents

    Zhang Li; Zhang Ming; Zhang Ling

    2010-01-01

    The nuclear engineering project documents with great quantity and various types of data, in which the relationships of each document are complex, the edition of document update frequently, are managed difficultly. While the safety of project even the nuclear safety is threatened seriously by the false documents and mistakes. In order to ensure the integrality, veracity and validity of project documents, the lifecycle theory of document is applied to build documents center, record center, structure and database of document lifecycle management system. And the lifecycle management is used to the documents of nuclear engineering projects from the production to pigeonhole, to satisfy the quality requirement of nuclear engineering projects. (authors)

  20. Lifecycle-analysis for heavy vehicles

    Gaines, L.

    1998-01-01

    Various alternative fuels and improved engine and vehicle systems have been proposed in order to reduce emissions and energy use associated with heavy vehicles (predominantly trucks). For example, oil companies have proposed improved methods for converting natural gas to zero-aromatics, zero-sulfur diesel fuel via the Fischer-Tropsch process. Major heavy-duty diesel engine companies are working on ways to simultaneously reduce particulate-matter and NOX emissions. The trend in heavy vehicles is toward use of lightweight materials, tires with lower rolling resistance, and treatments to reduce aerodynamic drag. In this paper, we compare the Mecycle energy use and emissions from trucks using selected alternatives, such as Fisher-Tropsch diesel fuel and advanced fuel-efficient engines. We consider heavy-duty, Class 8 tractor-semitrailer combinations for this analysis. The total life cycle includes production and recycling of the vehicle itself, extraction, processing, and transportation of the fuel itself, and vehicle operation and maintenance. Energy use is considered in toto, as well as those portions that are imported, domestic, and renewable. Emissions of interest include greenhouse gases and criteria pollutants. Angonne's Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation (GREET) model is used to generate per-vehicle fuel cycle impacts. Energy use and emissions for materials manufacturing and vehicle disposal are estimated by means of materials information from Argonne studies. We conclude that there are trade-offs among impacts. For example, the lowest fossil energy use does not necessarily result in lowest total energy use, and lower tailpipe emissions may not necessarily result in lower lifecycle emissions of all criteria pollutants

  1. The Life-cycle of Operons

    Price, Morgan N.; Arkin, Adam P.; Alm, Eric J.

    2007-03-15

    Operons are a major feature of all prokaryotic genomes, buthow and why operon structures vary is not well understood. To elucidatethe life-cycle of operons, we compared gene order between Escherichiacoli K12 and its relatives and identified the recently formed anddestroyed operons in E. coli. This allowed us to determine how operonsform, how they become closely spaced, and how they die. Our findingssuggest that operon evolution may be driven by selection on geneexpression patterns. First, both operon creation and operon destructionlead to large changes in gene expression patterns. For example, theremoval of lysA and ruvA from ancestral operons that contained essentialgenes allowed their expression to respond to lysine levels and DNAdamage, respectively. Second, some operons have undergone acceleratedevolution, with multiple new genes being added during a brief period.Third, although genes within operons are usually closely spaced becauseof a neutral bias toward deletion and because of selection against largeoverlaps, genes in highly expressed operons tend to be widely spacedbecause of regulatory fine-tuning by intervening sequences. Althoughoperon evolution may be adaptive, it need not be optimal: new operonsoften comprise functionally unrelated genes that were already inproximity before the operon formed.

  2. The Life-cycle of Operons

    Price, Morgan N.; Arkin, Adam P.; Alm, Eric J.

    2005-11-18

    Operons are a major feature of all prokaryotic genomes, but how and why operon structures vary is not well understood. To elucidate the life-cycle of operons, we compared gene order between Escherichia coli K12 and its relatives and identified the recently formed and destroyed operons in E. coli. This allowed us to determine how operons form, how they become closely spaced, and how they die. Our findings suggest that operon evolution is driven by selection on gene expression patterns. First, both operon creation and operon destruction lead to large changes in gene expression patterns. For example, the removal of lysA and ruvA from ancestral operons that contained essential genes allowed their expression to respond to lysine levels and DNA damage, respectively. Second, some operons have undergone accelerated evolution, with multiple new genes being added during a brief period. Third, although most operons are closely spaced because of a neutral bias towards deletion and because of selection against large overlaps, highly expressed operons tend to be widely spaced because of regulatory fine-tuning by intervening sequences. Although operon evolution seems to be adaptive, it need not be optimal: new operons often comprise functionally unrelated genes that were already in proximity before the operon formed.

  3. Materials Lifecycle and Environmental Consideration at NASA

    Clark-Ingram, Marceia

    2010-01-01

    The aerospace community faces tremendous challenges with continued availability of existing material supply chains during the lifecycle of a program. Many obsolescence drivers affect the availability of materials: environmental safety ahd health regulations, vendor and supply economics, market sector demands,and natural disasters. Materials selection has become increasingly more critical when designing aerospace hardware. NASA and DoD conducted a workshop with subject matter experts to discuss issues and define solutions for materials selections during the lifecycle phases of a product/system/component. The three primary lifecycle phases were: Conceptualization/Design, Production & Sustainment, and End of life / Reclamation. Materials obsolescence and pollution prevention considerations were explored for the aforementioned lifecycle phases. The recommended solutions from the workshop are being presented.

  4. Product Lifecycle Management and Sustainable Space Exploration

    Caruso, Pamela W.; Dumbacher, Daniel L.; Grieves, Michael

    2011-01-01

    This slide presentation reviews the use of product lifecycle management (PLM) in the general aerospace industry, its use and development at NASA and at Marshall Space Flight Center, and how the use of PLM can lead to sustainable space exploration.

  5. Life-Cycle Models for Survivable Systems

    Linger, Richard

    2002-01-01

    .... Current software development life-cycle models are not focused on creating survivable systems, and exhibit shortcomings when the goal is to develop systems with a high degree of assurance of survivability...

  6. Life-cycle assessment of Nebraska bridges.

    2013-05-01

    Life-cycle cost analysis (LCCA) is a necessary component in bridge management systems (BMSs) for : assessing investment decisions and identifying the most cost-effective improvement alternatives. The : LCCA helps to identify the lowest cost alternati...

  7. Product Lifecycle Management Centre of Technology

    Barnard, Rentia

    2017-10-01

    Full Text Available - Rentia Barnard.pdf.txt Content-Type text/plain; charset=UTF-8 1 Interactive activities Contents Product Lifecycle Management Centre of Technology Rentia Barnard National Industrialisation Support Initiative (NISI) 3 Initiative (NISI...

  8. Corporate entrepreneurship in organisational life-cycle

    Duobienė, Jurga

    2013-01-01

    Paper deals with the development of corporate entrepreneurship in different stages of organisational life-cycle. The research presents a model for the evaluation of corporate entrepreneurship and systemises relevant theoretical and empirical research in the field of entrepreneurship and corporate entrepreneurship. Moreover, it describes the development of corporate entrepreneurship in the entire organisational life-cycle since most of researchers who discuss the topics of corporate entreprene...

  9. A deterministic computer simulation model of life-cycle lamb and wool production.

    Wang, C T; Dickerson, G E

    1991-11-01

    A deterministic mathematical computer model was developed to simulate effects on life-cycle efficiency of lamb and wool production from genetic improvement of performance traits under alternative management systems. Genetic input parameters can be varied for age at puberty, length of anestrus, fertility, precocity of fertility, number born, milk yield, mortality, growth rate, body fat, and wool growth. Management options include mating systems, lambing intervals, feeding levels, creep feeding, weaning age, marketing age or weight, and culling policy. Simulated growth of animals is linear from birth to inflection point, then slows asymptotically to specified mature empty BW and fat content when nutrition is not limiting. The ME intake requirement to maintain normal condition is calculated daily or weekly for maintenance, protein and fat deposition, wool growth, gestation, and lactation. Simulated feed intake is the minimum of availability, DM physical limit, or ME physiological limit. Tissue catabolism occurs when intake is below the requirement for essential functions. Mortality increases when BW is depressed. Equations developed for calculations of biological functions were validated with published and unpublished experimental data. Lifetime totals are accumulated for TDN, DM, and protein intake and for market lamb equivalent output values of empty body or carcass lean and wool from both lambs and ewes. These measures of efficiency for combinations of genetic, management, and marketing variables can provide the relative economic weighting of traits needed to derive optimal criteria for genetic selection among and within breeds under defined industry production systems.

  10. Probabilistic risk analysis of aging components which fail on demand. A Bayesian model. Application to maintenance optimization of Diesel engine linings

    Procaccia, H.; Lannoy, A.; Clarotti, C.A.

    1997-01-01

    The optimization of preventive maintenance of aging materials can be well modelled through the application of the two-parameters Weibull law. Unfortunately there is no theoretical model describing the aging of components implied in emergency interventions which may fail in very moment of demand. These components are relevant to the safety of Nuclear Power Plants and the main problem with them is the optimization of the maintenance and the test schedule. Indeed the effect of any test is twofold, namely: the test reveals failures which otherwise would occur when the Power Plant would need urgent intervention but at the same time it causes the aging process to step up. The aging process is suspected to affect certain safeguard equipment, but it does not exist a theoretical model of component aging in function of demands. Sections 2.1 and 2.2 of the paper are devoted to the description of a Bayesian model of discrete aging, deriving the likelihood function of the model (data modelling) and to selecting 'the best prior' (Analyst knowledge) that can be associated to the likelihood, respectively. The aspects of numerical integration relative to assessing the predictive reliability of the aging components are discussed in Section 2.3. Section 3 reports a Reliability Centered Maintenance application of the model to cylinders of emergency electrical generators of the NPP nuclear sectors. These components are subjected to an annual endoscopic checking and to a systematical replacement at every 5 years. The statistical Bayesian decision theory was applied to determine an optimal period of cylinder replacement based on the aging model presented in this paper. It is shown that the optimal value is between 10 to 12 years. (author)

  11. The Software Life-Cycle Based Configuration Management Tasks for the KNICS Project

    Cheon, Se Woo; Kwon, Kee Choon

    2005-01-01

    Software configuration management (SCM) is an activity, which configures the form of a software system (e.g., design documents and programs) and systematically manages and controls the modifications used to compile the plans, development, and operations resulting from software development and maintenance. The SCM tool, NuSCM, has been specifically developed for the software life-cycle configuration management of developing the KNICS plant protection system (PPS). This paper presents the application of NuSCM to the KNICS project

  12. Consumption and Wage Humps in a Life-cycle Model with Education

    Kraft, Holger; Munk, Claus; Seifried, Frank Thomas

    The observed hump-shaped life-cycle pattern in individuals' consumption cannot be explained by the classical consumption-savings model. We explicitly solve a model with utility of both consumption and leisure and with educational decisions affecting future wages. We show optimal consumption is hump...

  13. Understanding future emissions from low-carbon power systems by integration of life-cycle assessment and integrated energy modelling

    Pehl, Michaja; Arvesen, Anders; Humpenöder, Florian; Popp, Alexander; Hertwich, Edgar G.; Luderer, Gunnar

    2017-12-01

    Both fossil-fuel and non-fossil-fuel power technologies induce life-cycle greenhouse gas emissions, mainly due to their embodied energy requirements for construction and operation, and upstream CH4 emissions. Here, we integrate prospective life-cycle assessment with global integrated energy-economy-land-use-climate modelling to explore life-cycle emissions of future low-carbon power supply systems and implications for technology choice. Future per-unit life-cycle emissions differ substantially across technologies. For a climate protection scenario, we project life-cycle emissions from fossil fuel carbon capture and sequestration plants of 78-110 gCO2eq kWh-1, compared with 3.5-12 gCO2eq kWh-1 for nuclear, wind and solar power for 2050. Life-cycle emissions from hydropower and bioenergy are substantial (˜100 gCO2eq kWh-1), but highly uncertain. We find that cumulative emissions attributable to upscaling low-carbon power other than hydropower are small compared with direct sectoral fossil fuel emissions and the total carbon budget. Fully considering life-cycle greenhouse gas emissions has only modest effects on the scale and structure of power production in cost-optimal mitigation scenarios.

  14. MAINTENANCE MANAGEMENT ACCOUNTING SYSTEM OF WASTE WATER DISPOSAL SYSTEMS

    Hori, Michihiro; Tsuruta, Takashi; Kaito, Kiyoyuki; Kobayashi, Kiyoshi

    Sewage works facilities consist of various assets groups. And there are many kinds of financial resources. In order to optimize the maintenance plan, and to secure the stability and sustainability of sewage works management, it is necessary to carry out financial simulation based on the life-cycle cost analysis. Furthermore, it is important to develop management accounting system that is interlinked with the financial accounting system, because many sewage administration bodies have their financial accounting systems as public enterprises. In this paper, a management accounting system, which is designed to provide basic information for asset management of sewage works facilities, is presented. Also the applicability of the management accounting system presented in this paper is examined through financial simulations.

  15. Reliability and life-cycle analysis of deteriorating systems

    Sánchez-Silva, Mauricio

    2016-01-01

    This book compiles and critically discusses modern engineering system degradation models and their impact on engineering decisions. In particular, the authors focus on modeling the uncertain nature of degradation considering both conceptual discussions and formal mathematical formulations. It also describes the basics concepts and the various modeling aspects of life-cycle analysis (LCA).  It highlights the role of degradation in LCA and defines optimum design and operation parameters. Given the relationship between operational decisions and the performance of the system’s condition over time, maintenance models are also discussed. The concepts and models presented have applications in a large variety of engineering fields such as Civil, Environmental, Industrial, Electrical and Mechanical engineering. However, special emphasis is given to problems related to large infrastructure systems. The book is intended to be used both as a reference resource for researchers and practitioners and as an academic text ...

  16. Product lifecycle management through innovative and competitive business environment

    Valentina Gecevska

    2010-10-01

    Full Text Available Product Lifecycle Management (PLM is the process of managing the whole life cycle of a product starting from generating an idea, concept description, business analyzes, product design and solution architecture and technical implementation, to the successful entrance to the market, service, maintenance and product improvement. At present, a wide range of stakeholders including consumers, regulators, shareholders and public bodies are demanding that companies address product management through all life cycle in a more comprehensive and sustainable way. However, even if a company actually wishes innovate its processes for improving the way to account for project management, it will face relevant difficulties to deal with different guidelines, tools and methods currently addressing the matter from various points of view. The purpose of this paper is to review literature on PLM from an operational point of view with the objective to help companies to answer to the main market needs.

  17. Product Lifecycle Management Technology Applied in Missile Launching Systems Production and Installation

    V. O. Karasev

    2016-01-01

    Full Text Available The article highlights the problems in the construction of the launch-site "Vostochniy" production and installation logistic. The stages of complex high-end product lifecycle described. The concepts and techniques of life cycle management and variants of their application offered as solution of this problems. Practical way to optimize logistics and lifecycle management processes using ILS Suite multi-agent software submitted. Side effect of this solution is creating of relevant integrated logistic support database, that could be used in the future projects. Results for tests and some perspectives for future investigation described.

  18. A multi-objective optimization model for energy-efficiency building envelope retrofitting plan with rooftop PV system installation and maintenance

    Fan, Yuling; Xia, Xiaohua

    2017-01-01

    Highlights: • A multi-objective optimization model for building envelope retrofit is presented. • Facility performance degradation and maintenance is built into the model. • A rooftop PV system is introduced to produce electricity. • Economic factors including net present value and payback period are considered. - Abstract: Retrofitting existing buildings with energy-efficient facilities is an effective method to improve their energy efficiency, especially for old buildings. A multi-objective optimization model for building envelope retrofitting is presented. Envelope components including windows, external walls and roofs are considered to be retrofitted. Installation of a rooftop solar panel system is also taken into consideration in this study. Rooftop solar panels are modeled with their degradation and a maintenance scheme is studied for sustainability of energy and its long-term effect on the retrofitting plan. The purpose is to make the best use of financial investment to maximize energy savings and economic benefits. In particular, net present value, the payback period and energy savings are taken as the main performance indicators of the retrofitting plan. The multi-objective optimization problem is formulated as a non-linear integer programming problem and solved by a weighted sum method. Results of applying the designed retrofitting plan to a 50-year-old building consisting of 66 apartments demonstrated the effectiveness of the proposed model.

  19. Structured life-cycle management: The case for starting now

    Fuller, E.; Crockett, J.

    1992-01-01

    The issuance of the US Nuclear Regulatory Commission (NRC) of the license renewal rule and the maintenance rule have presented a challenge to the nuclear industry to meet the requirements of both rules. These two rules afford an opportunity to provide a comprehensive, strategic approach to facility operation. A strategic approach is essential to integrate the processes and programs that are vying for resources within the organization and to take advantage of the opportunities available. This approach has been called structured life-cycle management (SLCM). The objectives of SLCM are to integrate the various utility programs and processes that bear directly on performance of the facility structures, systems, and components (SSCs) to (1) assure that SSC age-related issues are addressed effectively in utility maintenance and operations programs to preserve license-renewal options; (2) incorporate all existing utility maintenance and other related program benefits into one managed program (e.g., environmental qualification, design basis reconstitution, motor-operated valve testing, in-service inspection and test programs, and individual plant evaluations); and (3) maximize the benefits possible from the synergy of combining the various programs and processes in terms of enhanced safety, performance, and cost

  20. Deployable bamboo structure project: A building life-cycle report

    Firdaus, Adrian; Prastyatama, Budianastas; Sagara, Altho; Wirabuana, Revian N.

    2017-11-01

    Bamboo is considered as a sustainable material in the world of construction, and it is vastly available in Indonesia. The general utilization of the material is increasingly frequent, however, its usage as a deployable structure-a recently-developed use of bamboo, is still untapped. This paper presents a report on a deployable bamboo structure project, covering the entire building life-cycle phase. The cycle encompasses the designing; fabrication; transportation; construction; operation and maintenance; as well as a plan for future re-use. The building is made of a configuration of the structural module, each being a folding set of bars which could be reduced in size to fit into vehicles for easy transportation. Each structural module was made of Gigantochloa apus bamboo. The fabrication, transportation, and construction phase require by a minimum of three workers. The fabrication and construction phase require three hours and fifteen minutes respectively. The building is utilized as cafeteria stands, the operation and maintenance phase started since early March 2017. The maintenance plan is scheduled on a monthly basis, focusing on the inspection of the locking mechanism element and the entire structural integrity. The building is designed to allow disassembly process so that it is reusable in the future.

  1. Logistic optimization of maintenance management of pipeline network using operational research resources; Otimizacao logistica do gerenciamento de manutencoes na malha de gasodutos em operacao utilizando os recursos de pesquisa operacional

    Madeira, Italo M [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil); Andrade, Gustavo C. de [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil)

    2008-07-01

    A Gas pipeline system is operated typically loaded every time and requires a continuous maintenance plan to prevent or correct faults that can compromise the shipping and the delivery of the product. In this meaning, this paper describes how to provide more integration between the elements from the pipeline management logistics to do the scheduling tasks of maintenance using operational research resources. This tool intends to discover with an optimal result, the best days for each maintenance intervention in pipeline doing an economically distributed maintenance plan. (author)

  2. Future plans for performance analysis and maintenance/inspection optimization of shutoff rods based on the case study of Bruce Power Unit-3 Shutoff Rod 5 inspection

    Nasimi, E.; Gabbar, H.A.

    2011-01-01

    Shutdown System 1 (SDS1) is a preferred method for a quick shutdown of nuclear fission process in CANDU (CANada Deuterium Uranium) reactor units. Failure of a routine SDS1 safety test during Fall 2009 outage resulted in the need to develop and execute a new methodology for Shutoff Rod inspection and re-evaluate the known degradation mechanisms and failure modes. This paper describes the development of this methodology and the obtained results. It also proposes several alternative solutions for the future performance analysis and maintenance/inspection optimization for SDS1 Shutoff Rods based on the Bruce Power Unit-3 Shutoff Rod 5 case study. (author)

  3. Application of genetic algorithms to the maintenance scheduling optimization in a nuclear system basing on reliability; Aplicacao de algoritmos geneticos na otimizacao da politica de manutencoes preventivas de um sistema nuclear centrada em confiabilidade

    Lapa, Celso M. Franklin; Pereira, Claudio M.N.A.; Mol, Antonio C. de Abreu [Instituto de Engenharia Nuclear (IEN), Rio de Janeiro, RJ (Brazil)

    1999-07-01

    This paper presents a solution based on genetic algorithm and probabilistic safety analysis that can be applied in the optimization of the preventive maintenance politic of nuclear power plant safety systems. The goal of this approach is to improve the average availability of the system through the optimization of the preventive maintenance scheduling politic. The auxiliary feed water system of a two loops pressurized water reactor is used as a sample case, in order to demonstrate the effectiveness of the proposed method. The results, when compared to those obtained by some standard maintenance politics, reveal quantitative gains and operational safety levels. (author)

  4. Life-Cycle Cost-Benefit Analysis

    Thoft-Christensen, Palle

    2010-01-01

    The future use of Life-Cycle Cost-Benefit (LCCB) analysis is discussed in this paper. A more complete analysis including not only the traditional factors and user costs, but also factors which are difficult to include in the analysis is needed in the future.......The future use of Life-Cycle Cost-Benefit (LCCB) analysis is discussed in this paper. A more complete analysis including not only the traditional factors and user costs, but also factors which are difficult to include in the analysis is needed in the future....

  5. Research priorities at the European Commission in relation to maintenance optimization and nuclear power plant life management

    Contri, Paolo

    2009-01-01

    Analysis of experience in many countries operating nuclear power plants (NPPs) suggests that, while differences in long term operation (LTO) programs are mainly related to the various national regulatory processes, the main features and basic technical requirements are similar. The implementation of these however needs reshaping in an integrated plant life management (PLIM) framework, bearing in mind the specific safety implications of LTO. R and D is essential to support this process, not only for long term extrapolation of the component integrity and behaviour, but also for a proper maintenance system and for an adequate management structure ensuring effective management strategies at plant level, able to address organisational issues, spare part management, staff ageing, component obsolescence, etc. This is recognised by the European Commission, which supports R and D in targeted areas in the framework of the EURATOM programme, both by “direct actions” i.e. projects managed and executed by its Directorate General Joint Research Centers (JRC) and by indirect actions i.e. funding of selected projects, managed by the Directorate General Research (RTD). This paper outlines the JRC's priorities in the current 7th Framework Programme in relation to R and D tasks for maintenance and ISI to support the highest safety level at member's NPPs and appropriate decision-making tools for the optimisation of these programs. A newly developed UE model for PLIM, also integrating maintenance optimisation issues, is presented for further discussion. (author)

  6. Deterministic and stochastic approach for safety and reliability optimization of captive power plant maintenance scheduling using GA/SA-based hybrid techniques: A comparison of results

    Mohanta, Dusmanta Kumar; Sadhu, Pradip Kumar; Chakrabarti, R.

    2007-01-01

    This paper presents a comparison of results for optimization of captive power plant maintenance scheduling using genetic algorithm (GA) as well as hybrid GA/simulated annealing (SA) techniques. As utilities catered by captive power plants are very sensitive to power failure, therefore both deterministic and stochastic reliability objective functions have been considered to incorporate statutory safety regulations for maintenance of boilers, turbines and generators. The significant contribution of this paper is to incorporate stochastic feature of generating units and that of load using levelized risk method. Another significant contribution of this paper is to evaluate confidence interval for loss of load probability (LOLP) because some variations from optimum schedule are anticipated while executing maintenance schedules due to different real-life unforeseen exigencies. Such exigencies are incorporated in terms of near-optimum schedules obtained from hybrid GA/SA technique during the final stages of convergence. Case studies corroborate that same optimum schedules are obtained using GA and hybrid GA/SA for respective deterministic and stochastic formulations. The comparison of results in terms of interval of confidence for LOLP indicates that levelized risk method adequately incorporates the stochastic nature of power system as compared with levelized reserve method. Also the interval of confidence for LOLP denotes the possible risk in a quantified manner and it is of immense use from perspective of captive power plants intended for quality power

  7. Maintenance-Ready Web Application Development

    Ion IVAN

    2016-01-01

    Full Text Available The current paper tackles the subject of developing maintenance-ready web applications. Maintenance is presented as a core stage in a web application’s lifecycle. The concept of maintenance-ready is defined in the context of web application development. Web application maintenance tasks types are enunciated and suitable task types are identified for further analysis. The research hypothesis is formulated based on a direct link between tackling maintenance in the development stage and reducing overall maintenance costs. A live maintenance-ready web application is presented and maintenance related aspects are highlighted. The web application’s features, that render it maintenance-ready, are emphasize. The cost of designing and building the web-application to be maintenance-ready are disclosed. The savings in maintenance development effort facilitated by maintenance ready features are also disclosed. Maintenance data is collected from 40 projects implemented by a web development company. Homogeneity and diversity of collected data is evaluated. A data sample is presented and the size and comprehensive nature of the entire dataset is depicted. Research hypothesis are validated and conclusions are formulated on the topic of developing maintenance-ready web applications. The limits of the research process which represented the basis for the current paper are enunciated. Future research topics are submitted for debate.

  8. Cybersecurity and the Medical Device Product Development Lifecycle.

    Jones, Richard W; Katzis, Konstantinos

    2017-01-01

    Protecting connected medical devices from evolving cyber related threats, requires a continuous lifecycle approach whereby cybersecurity is integrated within the product development lifecycle and both complements and re-enforces the safety risk management processes therein. This contribution reviews the guidance relating to medical device cybersecurity within the product development lifecycle.

  9. A Life-Cycle Risk-Informed Systems Structured Nuclear Code

    Hill, Ralph S. III

    2002-01-01

    Current American Society of Mechanical Engineers (ASME) nuclear codes and standards rely primarily on deterministic and mechanistic approaches to design. The design code is a separate volume from the code for inservice inspections and both are separate from the standards for operations and maintenance. The ASME code for inservice inspections and code for nuclear plant operations and maintenance have adopted risk-informed methodologies for inservice inspection, preventive maintenance, and repair and replacement decisions. The American Institute of Steel Construction and the American Concrete Institute have incorporated risk-informed probabilistic methodologies into their design codes. It is proposed that the ASME nuclear code should undergo a planned evolution that integrates the various nuclear codes and standards and adopts a risk-informed approach across a facility life-cycle - encompassing design, construction, operation, maintenance and closure. (author)

  10. A lifecycle management program for NPP turbine balance of plant

    Manabe, Jun; Yamakami, Katsuhiko; Hiraoka, Satoshi; Kawai, Toshinari

    2009-01-01

    A lifecycle management program, for turbine balance of plant of light water reactor units which had been operated for more than 20 years but still having a long intended residual life time, was proposed and implemented from the view point of system and equipment supplier. Here would be introduced the program executed for several utilities. The program consists of unit surveillance analyzing both operation and inspection data, degradation assessment for the equipment and prospecting for the future by planning the proper measures for the issues based on both technology and economy. The program is introduced exampling the generating power affected by main steam pressure reduction derived from the scale adhesion and degradation of equipment. Multidisciplinary optimum design for the replacement of the feedwater heaters, one of the items of the planning, is introduced. Additionally would be introduced the new concept maintenance support program, mainly applied to the units already replaced their principal machines and auxiliaries, configured with both the condition based maintenance system monitoring the trend of parameters of a component and the diagnosis of malfunctions ascertaining the equipment by analyzing and synthesizing operation parameters. (author)

  11. Towards Agile Ontology Maintenance

    Luczak-Rösch, Markus

    Ontologies are an appropriate means to represent knowledge on the Web. Research on ontology engineering reached practices for an integrative lifecycle support. However, a broader success of ontologies in Web-based information systems remains unreached while the more lightweight semantic approaches are rather successful. We assume, paired with the emerging trend of services and microservices on the Web, new dynamic scenarios gain momentum in which a shared knowledge base is made available to several dynamically changing services with disparate requirements. Our work envisions a step towards such a dynamic scenario in which an ontology adapts to the requirements of the accessing services and applications as well as the user's needs in an agile way and reduces the experts' involvement in ontology maintenance processes.

  12. A Configuration System for Supportive Purposes in the Middle of a Product Lifecycle

    Christensen, Tim Teglgaard; Hvam, Lars

    2006-01-01

    for supportive purposes in the middle of a product lifecycle. By doing so a product in operation (including maintenance) could be administrated more effectively. At the same time it is a good opportunity to hand over important runtime information and thereby create a basis for general improvements......This paper presents a new way of using configuration systems. Traditionally, these systems have been use for decision support for sales. The aim is now to support "Middle-Of-Lifecycle" (MOL) processes, which means that the decision support system is targeted for the customers and the manufacturer...... (field services, technical support and after sales). This is especially interesting, as manufacturing companies are increasingly focusing their operations on service operations. The background for this idea is that companies often experience a lack of information between the initial sale...

  13. Development of methodologies for optimization of surveillance testing and maintenance of safety related equipment at NPPs. Report of a research coordination meeting. Working material

    NONE

    1997-09-01

    This report summarizes the results of the first meeting of the Coordinated Research Programme (CRP) on Development of Methodologies for Optimization of Surveillance Testing and Maintenance of Safety Related Equipment at NPPs, held at the Agency Headquarters in Vienna, from 16 to 20 December 1996. The purpose of this Research Coordination Meeting (RCM) was that all Chief Scientific Investigators of the groups participating in the CRP presented an outline of their proposed research projects. Additionally, the participants discussed the objective, scope, work plan and information channels of the CRP in detail. Based on these presentations and discussions, the entire project plan was updated, completed and included in this report. This report represents a common agreed project work plan for the CRP. Refs, figs, tabs.

  14. Life-cycle assessment of semiconductors

    Boyd, Sarah B

    2012-01-01

    Life-Cycle Assessment of Semiconductors presents the first and thus far only available transparent and complete life cycle assessment of semiconductor devices. A lack of reliable semiconductor LCA data has been a major challenge to evaluation of the potential environmental benefits of information technologies (IT). The analysis and results presented in this book will allow a higher degree of confidence and certainty in decisions concerning the use of IT in efforts to reduce climate change and other environmental effects. Coverage includes but is not limited to semiconductor manufacturing trends by product type and geography, unique coverage of life-cycle assessment, with a focus on uncertainty and sensitivity analysis of energy and global warming missions for CMOS logic devices, life cycle assessment of flash memory and life cycle assessment of DRAM. The information and conclusions discussed here will be highly relevant and useful to individuals and institutions. The book also: Provides a detailed, complete a...

  15. .net core application lifecycle on Openshift

    CERN. Geneva

    2017-01-01

    # .net core application lifecycle on Openshift I will show an example of a lifecycle of an OpenShift application with an emphasis on the continuous integration and deployment. The application compatible with [.net Standard](https://docs.microsoft.com/en-us/dotnet/standard/net-standard) can be easily deployed on OpenShift using [Source2Image](https://docs.openshift.com/enterprise/3.0/architecture/core_concepts/builds_and_image_streams.html#source-build) functionality, which doesn't require developers to maintain docker images of the application. I will also present how to efficiently integrate this feature into GitLab pipelines with an automated deployment of the "review" environment, as one its parts.

  16. Biomimicry of quorum sensing using bacterial lifecycle model.

    Niu, Ben; Wang, Hong; Duan, Qiqi; Li, Li

    2013-01-01

    Recent microbiologic studies have shown that quorum sensing mechanisms, which serve as one of the fundamental requirements for bacterial survival, exist widely in bacterial intra- and inter-species cell-cell communication. Many simulation models, inspired by the social behavior of natural organisms, are presented to provide new approaches for solving realistic optimization problems. Most of these simulation models follow population-based modelling approaches, where all the individuals are updated according to the same rules. Therefore, it is difficult to maintain the diversity of the population. In this paper, we present a computational model termed LCM-QS, which simulates the bacterial quorum-sensing (QS) mechanism using an individual-based modelling approach under the framework of Agent-Environment-Rule (AER) scheme, i.e. bacterial lifecycle model (LCM). LCM-QS model can be classified into three main sub-models: chemotaxis with QS sub-model, reproduction and elimination sub-model and migration sub-model. The proposed model is used to not only imitate the bacterial evolution process at the single-cell level, but also concentrate on the study of bacterial macroscopic behaviour. Comparative experiments under four different scenarios have been conducted in an artificial 3-D environment with nutrients and noxious distribution. Detailed study on bacterial chemotatic processes with quorum sensing and without quorum sensing are compared. By using quorum sensing mechanisms, artificial bacteria working together can find the nutrient concentration (or global optimum) quickly in the artificial environment. Biomimicry of quorum sensing mechanisms using the lifecycle model allows the artificial bacteria endowed with the communication abilities, which are essential to obtain more valuable information to guide their search cooperatively towards the preferred nutrient concentrations. It can also provide an inspiration for designing new swarm intelligence optimization algorithms

  17. Managing railcar maintenance : a primer on practices and improvement opportunities for the U.S. transit industry.

    2013-09-01

    This report surveys the state-of-practice of transit railcar maintenance management and fleet management practices. It emphasizes a lifecycle management approach to fleet management. It also emphasizes the role of performance improvement programs and...

  18. Product Lifecycle Management and the Quest for Sustainable Space Exploration Solutions

    Caruso, Pamela W.; Dumbacher, Daniel L.; Grieves, Michael

    2011-01-01

    Product Lifecycle Management (PLM) is an outcome of lean thinking to eliminate waste and increase productivity. PLM is inextricably tied to the systems engineering business philosophy, coupled with a methodology by which personnel, processes and practices, and information technology combine to form an architecture platform for product design, development, manufacturing, operations, and decommissioning. In this model, which is being implemented by the Marshall Space Flight Center (MSFC) Engineering Directorate, total lifecycle costs are important variables for critical decision-making. With the ultimate goal to deliver quality products that meet or exceed requirements on time and within budget, PLM is a powerful concept to shape everything from engineering trade studies and testing goals, to integrated vehicle operations and retirement scenarios. This briefing will demonstrate how the MSFC Engineering Directorate is implementing PLM as part of an overall strategy to deliver safe, reliable, and affordable space exploration solutions and how that strategy aligns with the Agency and Center systems engineering policies and processes. Sustainable space exploration solutions demand that all lifecycle phases be optimized, and engineering the next generation space transportation system requires a paradigm shift such that digital tools and knowledge management, which are central elements of PLM, are used consistently to maximum effect. Adopting PLM, which has been used by the aerospace and automotive industry for many years, for spacecraft applications provides a foundation for strong, disciplined systems engineering and accountable return on investment. PLM enables better solutions using fewer resources by making lifecycle considerations in an integrative decision-making process.

  19. Short-term planning and the life-cycle consumption puzzle

    Frank Caliendo; David Aadland

    2004-01-01

    This paper provides a new explanation for the hump-shaped age- consumption profile observed in household data. Standard life-cycle models are based on an optimization problem that spans the entire life expectancy. Alternatively, we examine the consumption profile of an individual with a shorter planning horizon. The actual consumption profile is the envelope of a continuum of control problems because the agent’s short-term planning horizon continually slides along the time- scale, and the age...

  20. Analysis of the Lifecycle of Mechanical Engineering Products

    Gubaidulina, Rauza Khamidovna; Gruby, S. V.; Davlatov, G. D.

    2016-01-01

    Principal phases of the lifecycle of mechanical engineering products are analyzed in the paper. The authors have developed methods and procedures to improve designing, manufacturing, operating and recycling of the machine. It has been revealed that economic lifecycle of the product is a base for appropriate organization of mechanical engineering production. This lifecycle is calculated as a minimal sum total of consumer and producer costs. The machine construction and its manufacturing techno...

  1. New Models for Maintenance of Offshore Wind Farms

    Petersen, Kristian R.

    component that was causing a large amount of downtime were identified. Further analysis with the Reliability-Centred Maintenance concept helped determine the most appropriate maintenance strategy. In the final perspective, long-term strategic decisions were the focus. Asset Management and especially Asset...... Life-Cycle Management were studied using a case study. The case study analysis was used to generate strategies to help managers perform maintenance more proactively and to prepare the management of the offshore wind farm turbines for the future. Existing literature on Asset Life-Cycle Management has......Operations and maintenance (O&M) processes are important for keeping offshore wind turbines in operation. Costs related to such activities constitute approximately 30% of the lifetime cost of an offshore wind farm project. Currently, the offshore wind energy industry has shown a rapid increase...

  2. Optimization of Installation, Operation and Maintenance at Offshore Wind Projects in the U.S.: Review and Modeling of Existing and Emerging Approaches

    Baldock, Nick [Garrad Hassan & Partners Ltd, Glasgow (United Kingdom); Sevilla, Fernando [Garrad Hassan & Partners Ltd, Glasgow (United Kingdom); Redfern, Robin [Garrad Hassan & Partners Ltd, Glasgow (United Kingdom); Storey, Alexis [Garrad Hassan & Partners Ltd, Glasgow (United Kingdom); Kempenaar, Anton [Garrad Hassan & Partners Ltd, Glasgow (United Kingdom); Elkinton, Chris [Garrad Hassan America, Inc., San Diego, CA (United States)

    2014-12-19

    The United States Department of Energy (DOE) awarded a grant to GL Garrad Hassan (GL GH) to investigate the logistics, opportunities, and costs associated with existing and emerging installation and operation and maintenance (O&M) activities at offshore wind projects as part of the DOE’s program to reduce barriers facing offshore wind project development in the United States (U.S.). This report (the Report) forms part of Subtopic 5.3 “Optimized Installation, Operation and Maintenance Strategies Study” which in turn is part of the “Removing Market Barriers in U.S. Offshore Wind” set of projects for the DOE. The purpose of Subtopic 5.3 is to aid and facilitate informed decision-making regarding installation and O&M during the development, installation, and operation of offshore wind projects in order to increase efficiency and reduce the levelized cost of energy (LCoE). Given the large area of U.S. territorial waters, the generally higher mean wind speeds offshore, and the proximity to the coast of many large U.S. cities, offshore wind power has the potential to become a significant contributor of energy to U.S. markets. However, for the U.S. to ensure that the development of offshore wind energy projects is carried out in an efficient and cost-effective manner, it is important to be cognizant of the current and emerging practices in both the domestic and international offshore wind energy industries. The U.S. can harness the experience gained globally and combine this with the skills and assets of an already sizeable onshore wind industry, as well as the resources of a mature offshore oil and gas industry, to develop a strong offshore wind sector. The work detailed in this report is aimed at assisting with that learning curve, particularly in terms of offshore specific installation and O&M activities. This Report and the Installation and O&M LCoE Analysis Tool, which were developed together by GL GH as part of this study, allow readers to identify, model

  3. Solar power satellite life-cycle energy recovery consideration

    Weingartner, S.; Blumenberg, J.

    The construction, in-orbit installation and maintenance of a solar power satellite (SPS) will demand large amounts of energy. As a minimum requirement for an energy effective power satellite it is asked that this amount of energy be recovered. The energy effectiveness in this sense resulting in a positive net energy balance is a prerequisite for cost-effective power satellite. This paper concentrates on life-cycle energy recovery instead on monetary aspects. The trade-offs between various power generation systems (different types of solar cells, solar dynamic), various construction and installation strategies (using terrestrial or extra-terrestrial resources) and the expected/required lifetime of the SPS are reviewed. The presented work is based on a 2-year study performed at the Technical University of Munich. The study showed that the main energy which is needed to make a solar power satellite a reality is required for the production of the solar power components (up to 65%), especially for the solar cell production. Whereas transport into orbit accounts in the order of 20% and the receiving station on earth (rectenna) requires about 15% of the total energy investment. The energetic amortization time, i.e. the time the SPS has to be operational to give back the amount of energy which was needed for its production installation and operation, is about two years.

  4. Comprehensive Lifecycle for Assuring System Safety

    Knight, John C.; Rowanhill, Jonathan C.

    2017-01-01

    CLASS is a novel approach to the enhancement of system safety in which the system safety case becomes the focus of safety engineering throughout the system lifecycle. CLASS also expands the role of the safety case across all phases of the system's lifetime, from concept formation to decommissioning. As CLASS has been developed, the concept has been generalized to a more comprehensive notion of assurance becoming the driving goal, where safety is an important special case. This report summarizes major aspects of CLASS and contains a bibliography of papers that provide additional details.

  5. Standardization: using comparative maintenance costs in an economic analysis

    Clark, Roger Nelson

    1987-01-01

    Approved for public release; distribution is unlimited This thesis investigates the use of comparative maintenance costs of functionally interchangeable equipments in similar U.S. Navy shipboard applications in an economic analysis of standardization. The economics of standardization, life-cycle costing, and the Navy 3-M System are discussed in general. An analysis of 3-M System maintenance costs for a selected equipment, diesel engines, is conducted. The potential use of comparative ma...

  6. Maintenance methods

    Sanchis, H.; Aucher, P.

    1990-01-01

    The maintenance method applied at the Hague is summarized. The method was developed in order to solve problems relating to: the different specialist fields, the need for homogeneity in the maintenance work, the equipment diversity, the increase of the materials used at the Hague's new facilities. The aim of the method is to create a knowhow formalism, to facilitate maintenance, to ensure the running of the operations and to improve the estimation of the maintenance cost. One of the method's difficulties is the demonstration of the profitability of the maintenance operations [fr

  7. Advances in safety related maintenance

    2000-03-01

    The maintenance of systems, structures and components in nuclear power plants (NPPs) plays an important role in assuring their safe and reliable operation. Worldwide, NPP maintenance managers are seeking to reduce overall maintenance costs while maintaining or improving the levels of safety and reliability. Thus, the issue of NPP maintenance is one of the most challenging aspects of nuclear power generation. There is a direct relation between safety and maintenance. While maintenance alone (apart from modifications) will not make a plant safer than its original design, deficient maintenance may result in either an increased number of transients and challenges to safety systems or reduced reliability and availability of safety systems. The confidence that NPP structures, systems and components will function as designed is ultimately based on programmes which monitor both their reliability and availability to perform their intended safety function. Because of this, approaches to monitor the effectiveness of maintenance are also necessary. An effective maintenance programme ensures that there is a balance between the improvement in component reliability to be achieved and the loss of component function due to maintenance downtime. This implies that the safety level of an NPP should not be adversely affected by maintenance performed during operation. The nuclear industry widely acknowledges the importance of maintenance in NPP safety and operation and therefore devotes great efforts to develop techniques, methods and tools to aid in maintenance planning, follow-up and optimization, and in assuring the effectiveness of maintenance

  8. Life-cycle Economic and Environmental Effects of Green, Gray and Hybrid Stormwater Infrastructure

    Stokes-Draut, J. R.; Taptich, M. N.; Horvath, A.

    2016-12-01

    Cities throughout the U.S. are seeking efficient ways to manage stormwater for many reasons, including flood control, pollution management, water supply augmentation and to prepare for a changing climate. Traditionally, cities have relied primarily on gray infrastructure, namely sewers, storage and treatment facilities. In these systems, urban runoff, its volume increasing as impervious surfaces expand, is channeled to a wastewater plant where it is mixed with raw sewage prior to treatment or it is discharged, generally untreated, to local water bodies. These facilities are inflexible and expensive to build and maintain. Many systems are deteriorating and/or approaching, if not exceeding, their design capacity. Increasingly, more innovative approaches that integrate stormwater management into the natural environment and that make sense at both local and regional scales are sought. Identifying the best stormwater solution will require evaluating the life-cycle economic costs associated with these alternatives, including costs associated with construction, operation, and maintenance including regulatory and permitting costs, financing, as well as other indirect costs (e.g., avoided wastewater processing or system capacity expansion, increased property value) and non-economic co-benefits (i.e, aesthetics, habitat provision). Beyond conventional life-cycle costing, applying life-cycle assessment (LCA) will contribute to more holistic and sustainable decision-making. LCA can be used to quantitatively track energy use, greenhouse gas emissions, and other environmental effects associated with constructing, operating, and maintaining green and gray infrastructure, including supply chain contributions. We will present the current state of knowledge for implementing life-cycle costing and LCA into stormwater management decisions for green, gray and hybrid infrastructure.

  9. Parking infrastructure: energy, emissions, and automobile life-cycle environmental accounting

    Chester, Mikhail; Horvath, Arpad; Madanat, Samer, E-mail: mchester@cal.berkeley.edu, E-mail: horvath@ce.berkeley.edu, E-mail: madanat@ce.berkeley.edu [Department of Civil and Environmental Engineering, University of California, Berkeley, Berkeley CA 94720 (United States)

    2010-07-15

    The US parking infrastructure is vast and little is known about its scale and environmental impacts. The few parking space inventories that exist are typically regionalized and no known environmental assessment has been performed to determine the energy and emissions from providing this infrastructure. A better understanding of the scale of US parking is necessary to properly value the total costs of automobile travel. Energy and emissions from constructing and maintaining the parking infrastructure should be considered when assessing the total human health and environmental impacts of vehicle travel. We develop five parking space inventory scenarios and from these estimate the range of infrastructure provided in the US to be between 105 million and 2 billion spaces. Using these estimates, a life-cycle environmental inventory is performed to capture the energy consumption and emissions of greenhouse gases, CO, SO{sub 2}, NO{sub X}, VOC (volatile organic compounds), and PM{sub 10} (PM: particulate matter) from raw material extraction, transport, asphalt and concrete production, and placement (including direct, indirect, and supply chain processes) of space construction and maintenance. The environmental assessment is then evaluated within the life-cycle performance of sedans, SUVs (sports utility vehicles), and pickups. Depending on the scenario and vehicle type, the inclusion of parking within the overall life-cycle inventory increases energy consumption from 3.1 to 4.8 MJ by 0.1-0.3 MJ and greenhouse gas emissions from 230 to 380 g CO{sub 2}e by 6-23 g CO{sub 2}e per passenger kilometer traveled. Life-cycle automobile SO{sub 2} and PM{sub 10} emissions show some of the largest increases, by as much as 24% and 89% from the baseline inventory. The environmental consequences of providing the parking spaces are discussed as well as the uncertainty in allocating paved area between parking and roadways.

  10. Life-cycle of fuel peat

    Leijting, J.; Silvo, K.

    1998-01-01

    The share of peat in the primary energy supply in Finland in 1996 was about 6.5 % and the area used for peat production was about 535 km 2 , corresponding to about 0.5 % of the original peatland area of Finland. Fuel peat production is hence a significant form of using natural resources. About 1.4 % of the total peatland area has been reserved for peat production. Approximately 95 % of the peat excavated in Finland is used as fuel peat, and 5 % as horticultural peat. As raw material and fuel peat can be considered to be slowly renewable material. The environmental impacts of fuel peat production, transportation and peat combustion were evaluated in this research by methods used in life-cycle assessment. Preparation and production phases of peat production areas, fuel peat transportation to power plants, combustion of peat in power plants, and disposal of the ashes formed the basis for the investigation. Data collected in 1994-1996 was used as the basic material in the research. Special attention was paid to the estimation of greenhouse gas balance when using a virgin bog and the forest drained peatland areas as starting points. Post-production use of peatlands were not inspected in the life-cycle assessment. The work was carried out in 1997 in cooperation with Vapo Oy. The regional environmental centers, VTT and Helsinki and Joensuu Universities assisted significantly in acquisition of the material and planning of the work 3 refs

  11. RAMS+C informed decision-making with application to multi-objective optimization of technical specifications and maintenance using genetic algorithms

    Martorell, S.; Villanueva, J.F.; Carlos, S.; Nebot, Y.; Sanchez, A.; Pitarch, J.L.; Serradell, V.

    2005-01-01

    The role of technical specifications and maintenance (TSM) activities at nuclear power plants (NPP) aims to increase reliability, availability and maintainability (RAM) of Safety-Related Equipment, which, in turn, must yield to an improved level of plant safety. However, more resources (e.g. costs, task force, etc.) have to be assigned in above areas to achieve better scores in reliability, availability, maintainability and safety (RAMS). Current situation at NPP shows different programs implemented at the plant that aim to the improvement of particular TSM-related parameters where the decision-making process is based on the assessment of the impact of the change proposed on a subgroup of RAMS+C attributes. This paper briefly reviews the role of TSM and two main groups of improvement programs at NPP, which suggest the convenience of considering the approach proposed in this paper for the Integrated Multi-Criteria Decision-Making on changes to TSM-related parameters based on RAMS+C criteria as a whole, as it can be seem as a decision-making process more consistent with the role and synergic effects of TSM and the objectives and goals of current improvement programs at NPP. The case of application to the Emergency Diesel Generator system demonstrates the viability and significance of the proposed approach for the Multi-objective Optimization of TSM-related parameters using a Genetic Algorithm

  12. Genetic algorithm-based optimization of testing and maintenance under uncertain unavailability and cost estimation: A survey of strategies for harmonizing evolution and accuracy

    Villanueva, J.F.; Sanchez, A.I.; Carlos, S.; Martorell, S.

    2008-01-01

    This paper presents the results of a survey to show the applicability of an approach based on a combination of distribution-free tolerance interval and genetic algorithms for testing and maintenance optimization of safety-related systems based on unavailability and cost estimation acting as uncertain decision criteria. Several strategies have been checked using a combination of Monte Carlo (simulation)--genetic algorithm (search-evolution). Tolerance intervals for the unavailability and cost estimation are obtained to be used by the genetic algorithms. Both single- and multiple-objective genetic algorithms are used. In general, it is shown that the approach is a robust, fast and powerful tool that performs very favorably in the face of noise in the output (i.e. uncertainty) and it is able to find the optimum over a complicated, high-dimensional nonlinear space in a tiny fraction of the time required for enumeration of the decision space. This approach reduces the computational effort by means of providing appropriate balance between accuracy of simulation and evolution; however, negative effects are also shown when a not well-balanced accuracy-evolution couple is used, which can be avoided or mitigated with the use of a single-objective genetic algorithm or the use of a multiple-objective genetic algorithm with additional statistical information

  13. Product Lifecycle Management Architecture: A Model Based Systems Engineering Analysis.

    Noonan, Nicholas James [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-07-01

    This report is an analysis of the Product Lifecycle Management (PLM) program. The analysis is centered on a need statement generated by a Nuclear Weapons (NW) customer. The need statement captured in this report creates an opportunity for the PLM to provide a robust service as a solution. Lifecycles for both the NW and PLM are analyzed using Model Based System Engineering (MBSE).

  14. Life-cycle optimization model for distributed generation in buildings

    Safaei, Amir

    O setor da construcao e responsavel por uma grande parte do consumo de energia e emissoes na Uniao Europeia. A Geracao Distribuida (GD) de energia, nomeadamente atraves de sistemas de cogeracao e tecnologias solares, representa um papel importante no futuro energetico deste setor. A otimizacao do funcionamento dos sistemas de cogeracao e uma tarefa complexa, devido as diversas variaveis em jogo, designadamente: os diferentes tipos de necessidades energeticas (eletricidade, aquecimento e arrefecimento), os precos dinamicos dos combustiveis (gas natural) e da eletricidade, e os custos fixos e variaveis dos diferentes sistemas de GD. Tal torna-se mais complexo considerando a natureza flutuante das tecnologias solares termicas e fotovoltaicas. Ao mesmo tempo, a liberalizacao do mercado da eletricidade permite exportar para a rede, a electricidade gerada localmente. Adicionalmente, a operacao estrategica de um sistema de GD deve atender aos quadros politicos nacionais, se tiver como objetivo beneficiar de tais regimes. Alem disso, considerando os elevados impactes ambientais do setor da construcao, qualquer avaliacao energetica de edificios rigorosa deve tambem integrar aspetos ambientais, utilizando uma abordagem de Ciclo de Vida (CV). Uma avaliacao de Ciclo de Vida (ACV) completa de um sistema de GD deve incluir as fases relativas a operacao e construcao do sistema, bem como os impactes associados a producao dos combustiveis. Foram analisadas as emissoes da producao de GN, as quais variam de acordo com a origem, tipo (convencional ou nao-convencional), e estado (na forma de GN Liquefeito (GNL) ou gas). Do mesmo modo, o impacte dos sistemas solares e afetado pela meteorologia e radiacao solar, de acordo com a sua localizacao geografica. Sendo assim, uma avaliacao adequada dos sistemas de GD exige um modelo de ACV adequado a localizacao geografica (Portugal), integrando tambem a producao de combustivel (GN), tendo em conta as suas diferentes fontes de abastecimento. O principal objetivo desta tese de doutoramento foi desenvolver um modelo para otimizar o desenho e operacao de sistemas de GD para o setor da construcao de edificios comerciais em Portugal, considerando os respetivos Impactes de Ciclo de Vida (IAVC) e Custos de Ciclo de Vida (CCV), de modo a satisfazer as necessidades energeticas do edificio. Tres tipos de tecnologias de cogeracao (Micro-Turbinas, Motores de combustao interna, e Celulas combustiveis de Oxido solido), e dois tipos de tecnologias de energia solar, solar termica e fotovoltaica, constituem os sistemas de GD que sao acoplados aos sistemas convencionais. Foi desenvolvido um modelo de CV, tendo em conta todos os impactes relacionados com a construcao e operacao dos sistemas de energia, bem como os processos a montante relacionados com a producao do GN. Em particular, o mix de GN consumido em Portugal em 2011 foi identificado (60% da Nigeria, 40% da Argelia) e os impactes relativos a cada uma das vias de abastecimento foram avaliados separadamente para quatro categorias de impacte ambiental: Consumo de Energia Primaria (CEP), Gases com Efeito de Estufa (GEE), acidificacao, e eutrofizacao. Devido a importancia das emissoes de GEE na formulacao de politicas, foi tambem realizada uma analise de incerteza as emissoes de GEE do GN fornecido a Portugal. Foi desenvolvido um modelo matematico, em linguagem de Programacao General Algebraic Modeling System (GAMS), que utiliza os resultados da ACV dos sistemas de energia e as suas implicacoes economicas para minimizar o CCV e IACV ao longo de um horizonte de planeamento definido pelo decisor. Foram derivadas fronteiras otimas de Pareto, representando as relacoes entre o tipo de IACV (CEP, GEE, acidificacao, eutrofizacao) e CCV decorrentes da satisfacao das necessidades energeticas do edificio. Para aumentar a robustez do modelo, dada a incerteza dos precos dos combustiveis (GN e eletricidade), foi desenvolvido um modelo de custos robusto para os sistemas de GD, que e menos afetado por perturbacoes relativas aos custos de combustivel. A aplicacao do modelo proposto foi testada num caso de estudo real, um edificio comercial localizado na cidade de Coimbra, em Portugal.

  15. Optimization of maintenance scheduling with genetic algorithms regarding the storage behavior during the availability prognosis of power plants; Optimierung der Instandhaltungsplanung mit genetischen Algorithmen unter Beruecksichtigung des Speicherverhaltens bei der Verfuegbarkeitsprognose von Kraftwerksanlagen

    Warnecke, Martin

    2008-12-19

    In the age of the liberalized energy market the power plant raisers and operators have to consider several factors when choosing the fuel type and dimensioning their power plants, e.g. emissions, erection cost and last but not least operating cost. Simulations assuming different scenarios are required. The rivaling aspects of erection cost, partially dependant availability, maintenance philosophy and operating cost are motivating the optimization of maintenance scheduling and the availability prognosis which are the topic of this thesis. The focus of this thesis is on the scheduling of the time based maintenance strategy. This strategy defines the time spans between the repeating inspections of each component. This is based on the experience of operators and manufacturers. The mathematic problem itself is especially challenging because of strong interdependencies between the single components due to synergy effects. Each component has its own theoretically optimal lifetime and maintenance period. Yet as part of a compound it might be more cost efficient in the long run to maintain some components together shifting some of them forward or backward. The thereby caused interdependencies constitute a non-linear, mixed-whole-numbered calculation of the cost approximation. For the optimization of this maintenance scheduling a new approach was developed. It was realized that the problem couldn't be solved satisfyingly with classic optimization algorithms. Afterwards a solution based on ''genetic algorithms'' was developed. In the meantime the methods for the availability prognosis of complex power plant facilities were enhanced. Especially a new component with storage behavior (with optional losses) was added to the prognosis tool. This storage model integrates the behavior of a storage into the computing time reduced Monte-Carlo-Method. (orig.)

  16. Preventative Maintenance.

    Migliorino, James

    Boards of education must be convinced that spending money up front for preventive maintenance will, in the long run, save districts' tax dollars. A good program of preventive maintenance can minimize disruption of service; reduce repair costs, energy consumption, and overtime; improve labor productivity and system equipment reliability; handle…

  17. CAME-Computer Aided Maintenance Engineering: a new methodology to reduce maintenance life cycle cost pipelines (repair level, spares, preventive/scheduled/inspection and resources) by modeling, analysis and optimization

    Bot, Yizhak [BQR Reliability Engineering Ltd. (Israel)

    2005-07-01

    In today's insecure and uncertain climate in the high-tech industry, where money is less accessible, companies are constantly searching for ways to cut expenses. Two important financial factors to consider are maintenance and down time when the equipment/system/processes are not functioning/operating. In this paper we shall describe a new technology, which will help designers and operators of complex systems to improve the reliability of the products and to reduce the maintenance cost, when they are used in field. These set of tools are interfaced to exist CAD/CAE and ERP/CMMS systems concurrently. (author)

  18. PRODUCT LIFECYCLE OPTIMISATION OF CAR CLIMATE CONTROLS USING ANALYTICAL HIERARCHICAL PROCESS (AHP ANALYSIS AND A MULTI-OBJECTIVE GROUPING GENETIC ALGORITHM (MOGGA

    MICHAEL J. LEE

    2016-01-01

    Full Text Available A product’s lifecycle performance (e.g. assembly, outsourcing, maintenance and recycling can often be improved through modularity. However, modularisation under different and often conflicting lifecycle objectives is a complex problem that will ultimately require trade-offs. This paper presents a novel multi-objective modularity optimisation framework; the application of which is illustrated through the modularisation of a car climate control system. Central to the framework is a specially designed multi-objective grouping genetic algorithm (MOGGA that is able to generate a whole range of alternative product modularisations. Scenario analysis, using the principles of the analytical hierarchical process (AHP, is then carried out to explore the solution set and choose a suitable modular architecture that optimises the product lifecycle according to the company’s strategic vision.

  19. Lifecycle cost assessment and carbon dioxide emissions of diesel, natural gas, hybrid electric, fuel cell hybrid and electric transit buses

    Lajunen, Antti; Lipman, Timothy

    2016-01-01

    This paper evaluates the lifecycle costs and carbon dioxide emissions of different types of city buses. The simulation models of the different powertrains were developed in the Autonomie vehicle simulation software. The carbon dioxide emissions were calculated both for the bus operation and for the fuel and energy pathways from well to tank. Two different operating environment case scenarios were used for the primary energy sources, which were Finland and California (USA). The fuel and energy pathways were selected appropriately in relation to the operating environment. The lifecycle costs take into account the purchase, operating, maintenance, and possible carbon emission costs. Based on the simulation results, the energy efficiency of city buses can be significantly improved by the alternative powertrain technologies. Hybrid buses have moderately lower carbon dioxide emissions during the service life than diesel buses whereas fully-electric buses have potential to significantly reduce carbon dioxide emissions, by up to 75%. The lifecycle cost analysis indicates that diesel hybrid buses are already competitive with diesel and natural gas buses. The high costs of fuel cell and battery systems are the major challenges for the fuel cell hybrid buses in order to reduce lifecycle costs to more competitive levels. - Highlights: • Alternative powertrains can significantly improve energy efficiency of transit buses. • Operating environment has an important impact on the lifecycle costs of buses. • Diesel hybrid buses are already cost effective solution for public transportation. • The cost of fuel cell technology is the major challenge for fuel cell hybrid buses. • Fully-electric buses have potential to significantly reduce carbon dioxide emissions.

  20. A Lifecycle Emissions Model (LEM): Lifecycle Emissions from Transportation Fuels, Motor Vehicles, Transportation Modes, Electricity Use, Heating and Cooking Fuels, and Materials, APPENDIX A: Energy Use and Emissions from the Lifecycle of Diesel-Like Fuels Derived From Biomass

    Delucchi, Mark; Lipman, Timothy

    2003-01-01

    An Appendix to the Report, “A Lifecycle Emissions Model (LEM): Lifecycle Emissions From Transportation Fuels, Motor Vehicles, Transportation Modes, Electricity Use, Heating and Cooking Fuels, and Materialsâ€

  1. A life-cycle comparison of alternative automobile fuels.

    MacLean, H L; Lave, L B; Lankey, R; Joshi, S

    2000-10-01

    We examine the life cycles of gasoline, diesel, compressed natural gas (CNG), and ethanol (C2H5OH)-fueled internal combustion engine (ICE) automobiles. Port and direct injection and spark and compression ignition engines are examined. We investigate diesel fuel from both petroleum and biosources as well as C2H5OH from corn, herbaceous bio-mass, and woody biomass. The baseline vehicle is a gasoline-fueled 1998 Ford Taurus. We optimize the other fuel/powertrain combinations for each specific fuel as a part of making the vehicles comparable to the baseline in terms of range, emissions level, and vehicle lifetime. Life-cycle calculations are done using the economic input-output life-cycle analysis (EIO-LCA) software; fuel cycles and vehicle end-of-life stages are based on published model results. We find that recent advances in gasoline vehicles, the low petroleum price, and the extensive gasoline infrastructure make it difficult for any alternative fuel to become commercially viable. The most attractive alternative fuel is compressed natural gas because it is less expensive than gasoline, has lower regulated pollutant and toxics emissions, produces less greenhouse gas (GHG) emissions, and is available in North America in large quantities. However, the bulk and weight of gas storage cylinders required for the vehicle to attain a range comparable to that of gasoline vehicles necessitates a redesign of the engine and chassis. Additional natural gas transportation and distribution infrastructure is required for large-scale use of natural gas for transportation. Diesel engines are extremely attractive in terms of energy efficiency, but expert judgment is divided on whether these engines will be able to meet strict emissions standards, even with reformulated fuel. The attractiveness of direct injection engines depends on their being able to meet strict emissions standards without losing their greater efficiency. Biofuels offer lower GHG emissions, are sustainable, and

  2. A Life-Cycle Comparison of Alternative Automobile Fuels.

    MacLean, Heather L; Lave, Lester B; Lankey, Rebecca; Joshi, Satish

    2000-10-01

    We examine the life cycles of gasoline, diesel, compressed natural gas (CNG), and ethanol (C 2 H 5 OH)-fueled internal combustion engine (ICE) automobiles. Port and direct injection and spark and compression ignition engines are examined. We investigate diesel fuel from both petroleum and biosources as well as C 2 H 5 OH from corn, herbaceous bio-mass, and woody biomass. The baseline vehicle is a gasoline-fueled 1998 Ford Taurus. We optimize the other fuel/powertrain combinations for each specific fuel as a part of making the vehicles comparable to the baseline in terms of range, emissions level, and vehicle lifetime. Life-cycle calculations are done using the economic input-output life-cycle analysis (EIO-LCA) software; fuel cycles and vehicle end-of-life stages are based on published model results. We find that recent advances in gasoline vehicles, the low petroleum price, and the extensive gasoline infrastructure make it difficult for any alternative fuel to become commercially viable. The most attractive alternative fuel is compressed natural gas because it is less expensive than gasoline, has lower regulated pollutant and toxics emissions, produces less greenhouse gas (GHG) emissions, and is available in North America in large quantities. However, the bulk and weight of gas storage cylinders required for the vehicle to attain a range comparable to that of gasoline vehicles necessitates a redesign of the engine and chassis. Additional natural gas transportation and distribution infrastructure is required for large-scale use of natural gas for transportation. Diesel engines are extremely attractive in terms of energy efficiency, but expert judgment is divided on whether these engines will be able to meet strict emissions standards, even with reformulated fuel. The attractiveness of direct injection engines depends on their being able to meet strict emissions standards without losing their greater efficiency. Biofuels offer lower GHG emissions, are sustainable

  3. Maintenance Mentor

    Jacobs, John

    2003-01-01

    Maintenance Mentor (MXM) is a research effort conducted by a joint AFRL/HESR and Northrop Grumman Information Technology team to identify the basic, high-level requirements necessary for improving flight line diagnostic capabilities...

  4. Product Lifecycle Management: CERN to host an important international conference

    CERN Bulletin

    2011-01-01

    CERN designs, builds and operates machines that contain millions of items of many types, such as software, electronics, and electrical, mechanical and chemical components. It is a challenge to maintain a coherent configuration of everything that has been developed and installed. To do this, CERN developed the EDMS system – an integrated Product Lifecycle Management (PLM) platform that enables management of all the information related to the entire lifecycle of each single component. On 5 and 6 September CERN will host an international PLM conference at which participants will exchange experience and address how best to apply PLM in their organisations.   Pictogram representation of a typical product lifecycle. Picture by the National Institute of Standards and Technology’s Manufacturing Engineering via Wikimedia Commons [Public domain]. PLM is the activity of managing, in the most effective way, an organisation’s products all the way through their lifecycles: from th...

  5. Instrumentation maintenance

    Mack, D.A.

    1976-09-01

    It is essential to any research activity that accurate and efficient measurements be made for the experimental parameters under consideration for each individual experiment or test. Satisfactory measurements in turn depend upon having the necessary instruments and the capability of ensuring that they are performing within their intended specifications. This latter requirement can only be achieved by providing an adequate maintenance facility, staffed with personnel competent to understand the problems associated with instrument adjustment and repair. The Instrument Repair Shop at the Lawrence Berkeley Laboratory is designed to achieve this end. The organization, staffing and operation of this system is discussed. Maintenance policy should be based on studies of (1) preventive vs. catastrophic maintenance, (2) records indicating when equipment should be replaced rather than repaired and (3) priorities established to indicate the order in which equipment should be repaired. Upon establishing a workable maintenance policy, the staff should be instructed so that they may provide appropriate scheduled preventive maintenance, calibration and corrective procedures, and emergency repairs. The education, training and experience of the maintenance staff is discussed along with the organization for an efficient operation. The layout of the various repair shops is described in the light of laboratory space and financial constraints

  6. Life-cycle analysis of renewable energy systems

    Sørensen, Bent

    1994-01-01

    An imlementation of life-cycle analysis (LCA) for energy systems is presented and applied to two renewable energy systems (wind turbines and building-integrated photovoltaic modules) and compared with coal plants......An imlementation of life-cycle analysis (LCA) for energy systems is presented and applied to two renewable energy systems (wind turbines and building-integrated photovoltaic modules) and compared with coal plants...

  7. Life-cycle energy of residential buildings in China

    Chang, Yuan; Ries, Robert J.; Wang, Yaowu

    2013-01-01

    In the context of rapid urbanization and new construction in rural China, residential building energy consumption has the potential to increase with the expected increase in demand. A process-based hybrid life-cycle assessment model is used to quantify the life-cycle energy use for both urban and rural residential buildings in China and determine the energy use characteristics of each life cycle phase. An input–output model for the pre-use phases is based on 2007 Chinese economic benchmark data. A process-based life-cycle assessment model for estimating the operation and demolition phases uses historical energy-intensity data. Results show that operation energy in both urban and rural residential buildings is dominant and varies from 75% to 86% of life cycle energy respectively. Gaps in living standards as well as differences in building structure and materials result in a life-cycle energy intensity of urban residential buildings that is 20% higher than that of rural residential buildings. The life-cycle energy of urban residential buildings is most sensitive to the reduction of operational energy intensity excluding heating energy which depends on both the occupants' energy-saving behavior as well as the performance of the building itself. -- Highlights: •We developed a hybrid LCA model to quantify the life-cycle energy for urban and rural residential buildings in China. •Operation energy in urban and rural residential buildings is dominant, varying from 75% to 86% of life cycle energy respectively. •Compared with rural residential buildings, the life-cycle energy intensity of urban residential buildings is 20% higher. •The life-cycle energy of urban residential buildings is most sensitive to the reduction of daily activity energy

  8. Maintenance management for nuclear power plant 'Integrated valve maintenance'

    Gerner, P.; Zanner, G.

    2001-01-01

    The deregulation of Europe's power market does force many utilities, and especially nuclear power plant operators, to introduce extensive cost-cutting measures in order to be able to compete within this new environment. The optimization of plant outages provides considerable potential for raising plant availability but can also lower operating costs by reducing e.g. expenditure on maintenance. Siemens Nuclear Power GmbH, in cooperation with plant operators, is currently implementing new and improved service concepts which can have a major effect on the way in which maintenance will be performed in the future. Innovative service packages for maintenance in nuclear power plants are available which can be used to perform a time- and cost-effective maintenance. The concepts encompass optimization of the overall sequence from planning in advance to the individual measures including reduction of the scope of maintenance activities, identification of cost cutting potential and bundling of maintenance activities. The main features of these maintenance activities are illustrated here using the examples of outage planning and integrated valve maintenance. In nuclear power plants approx. 5000 valves are periodically preventively, condition-based or breakdown-based maintained. Because of this large number of valves to be maintained a high potential of improvements and cost reductions can be achieved by performing an optimized, cost-effective maintenance based on innovative methods and tools. Siemens Nuclear Power GmbH has developed and qualified such tools which allow to reduce service costs while maintaining high standards of safety and availability. By changing from preventive to predictive (condition-based) maintenance - the number of valves to be maintained may be reduced considerably. The predictive maintenance is based on the Siemens Nuclear Power GmbH diagnostic and evaluation method (ADAM). ADAM is used to monitor the operability of valves by analytical verification of

  9. The Role of Distribution Infrastructure and Equipment in the Life-cycle Air Emissions of Liquid Transportation Fuels

    Strogen, Bret Michael

    Production of fuel ethanol in the United States has increased ten-fold since 1993, largely as a result of government programs motivated by goals to improve domestic energy security, economic development, and environmental impacts. Over the next decade, the growth of and eventually the total production of second generation cellulosic biofuels is projected to exceed first generation (e.g., corn-based) biofuels, which will require continued expansion of infrastructure for producing and distributing ethanol and perhaps other biofuels. In addition to identifying potential differences in tailpipe emissions from vehicles operating with ethanol-blended or ethanol-free gasoline, environmental comparison of ethanol to petroleum fuels requires a comprehensive accounting of life-cycle environmental effects. Hundreds of published studies evaluate the life-cycle emissions from biofuels and petroleum, but the operation and maintenance of storage, handling, and distribution infrastructure and equipment for fuels and fuel feedstocks had not been adequately addressed. Little attention has been paid to estimating and minimizing emissions from these complex systems, presumably because they are believed to contribute a small fraction of total emissions for petroleum and first generation biofuels. This research aims to quantify the environmental impacts associated with the major components of fuel distribution infrastructure, and the impacts that will be introduced by expanding the parallel infrastructure needed to accommodate more biofuels in our existing systems. First, the components used in handling, storing, and transporting feedstocks and fuels are physically characterized by typical operating throughput, utilization, and lifespan. US-specific life-cycle GHG emission and water withdrawal factors are developed for each major distribution chain activity by applying a hybrid life-cycle assessment methodology to the manufacturing, construction, maintenance and operation of each

  10. Development and Validation of a Lifecycle-based Prognostics Architecture with Test Bed Validation

    Hines, J. Wesley [Univ. of Tennessee, Knoxville, TN (United States); Upadhyaya, Belle [Univ. of Tennessee, Knoxville, TN (United States); Sharp, Michael [Univ. of Tennessee, Knoxville, TN (United States); Ramuhalli, Pradeep [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Jeffries, Brien [Univ. of Tennessee, Knoxville, TN (United States); Nam, Alan [Univ. of Tennessee, Knoxville, TN (United States); Strong, Eric [Univ. of Tennessee, Knoxville, TN (United States); Tong, Matthew [Univ. of Tennessee, Knoxville, TN (United States); Welz, Zachary [Univ. of Tennessee, Knoxville, TN (United States); Barbieri, Federico [Univ. of Tennessee, Knoxville, TN (United States); Langford, Seth [Univ. of Tennessee, Knoxville, TN (United States); Meinweiser, Gregory [Univ. of Tennessee, Knoxville, TN (United States); Weeks, Matthew [Univ. of Tennessee, Knoxville, TN (United States)

    2014-11-06

    RUL predictions, with as little uncertainty as possible. From a reliability and maintenance standpoint, there would be improved safety by avoiding all failures. Calculated risk would decrease, saving money by avoiding unnecessary maintenance. One major bottleneck for data-driven prognostics is the availability of run-to-failure degradation data. Without enough degradation data leading to failure, prognostic models can yield RUL distributions with large uncertainty or mathematically unsound predictions. To address these issues a "Lifecycle Prognostics" method was developed to create RUL distributions from Beginning of Life (BOL) to End of Life (EOL). This employs established Type I, II, and III prognostic methods, and Bayesian transitioning between each Type. Bayesian methods, as opposed to classical frequency statistics, show how an expected value, a priori, changes with new data to form a posterior distribution. For example, when you purchase a component you have a prior belief, or estimation, of how long it will operate before failing. As you operate it, you may collect information related to its condition that will allow you to update your estimated failure time. Bayesian methods are best used when limited data are available. The use of a prior also means that information is conserved when new data are available. The weightings of the prior belief and information contained in the sampled data are dependent on the variance (uncertainty) of the prior, the variance (uncertainty) of the data, and the amount of measured data (number of samples). If the variance of the prior is small compared to the uncertainty of the data, the prior will be weighed more heavily. However, as more data are collected, the data will be weighted more heavily and will eventually swamp out the prior in calculating the posterior distribution of model parameters. Fundamentally Bayesian analysis updates a prior belief with new data to get a posterior belief. The general approach to applying the

  11. On Lifecycle Constraints of Artifact-Centric Workflows

    Kucukoguz, Esra; Su, Jianwen

    Data plays a fundamental role in modeling and management of business processes and workflows. Among the recent "data-aware" workflow models, artifact-centric models are particularly interesting. (Business) artifacts are the key data entities that are used in workflows and can reflect both the business logic and the execution states of a running workflow. The notion of artifacts succinctly captures the fluidity aspect of data during workflow executions. However, much of the technical dimension concerning artifacts in workflows is not well understood. In this paper, we study a key concept of an artifact "lifecycle". In particular, we allow declarative specifications/constraints of artifact lifecycle in the spirit of DecSerFlow, and formulate the notion of lifecycle as the set of all possible paths an artifact can navigate through. We investigate two technical problems: (Compliance) does a given workflow (schema) contain only lifecycle allowed by a constraint? And (automated construction) from a given lifecycle specification (constraint), is it possible to construct a "compliant" workflow? The study is based on a new formal variant of artifact-centric workflow model called "ArtiNets" and two classes of lifecycle constraints named "regular" and "counting" constraints. We present a range of technical results concerning compliance and automated construction, including: (1) compliance is decidable when workflow is atomic or constraints are regular, (2) for each constraint, we can always construct a workflow that satisfies the constraint, and (3) sufficient conditions where atomic workflows can be constructed.

  12. Towards a Lifecycle Information Framework and Technology in Manufacturing.

    Hedberg, Thomas; Feeney, Allison Barnard; Helu, Moneer; Camelio, Jaime A

    2017-06-01

    Industry has been chasing the dream of integrating and linking data across the product lifecycle and enterprises for decades. However, industry has been challenged by the fact that the context in which data is used varies based on the function / role in the product lifecycle that is interacting with the data. Holistically, the data across the product lifecycle must be considered an unstructured data-set because multiple data repositories and domain-specific schema exist in each phase of the lifecycle. This paper explores a concept called the Lifecycle Information Framework and Technology (LIFT). LIFT is a conceptual framework for lifecycle information management and the integration of emerging and existing technologies, which together form the basis of a research agenda for dynamic information modeling in support of digital-data curation and reuse in manufacturing. This paper provides a discussion of the existing technologies and activities that the LIFT concept leverages. Also, the paper describes the motivation for applying such work to the domain of manufacturing. Then, the LIFT concept is discussed in detail, while underlying technologies are further examined and a use case is detailed. Lastly, potential impacts are explored.

  13. Adenomyosis: a life-cycle approach.

    Benagiano, Giuseppe; Brosens, Ivo; Habiba, Marwan

    2015-03-01

    The life-cycle approach to endometriosis highlighted unexpected features of the condition; the same approach was therefore applied to gain insight into the clinical features of adenomyosis and to draw a comparison with endometriosis. This is possible today thanks to new imaging techniques enabling non-invasive diagnosis of adenomyosis. The specificity and sensitivity of magnetic resonance imaging and transvaginal ultrasound remain uncertain. Unlike endometriosis, little information is available on the presence of classic adenomyosis in adolescents, except for rare cystic forms that may not represent the true disease. Adenomyosis is most likely to affect adult women, although most reported incidences are still based on post-hysterectomy studies, and are affected by diligence in histopathologic diagnosis and the adopted cut-off point. The traditionally accepted associations of adult adenomyosis, such as multiparity, a link to infertility and its effect on pregnancy are uncertain. Active adenomyosis has been found in pre- and peri-menopausal women and in postmenopausal women receiving tamoxifen. In conclusion, major diagnostic limitations and the systematic bias of hysterectomy make it difficult to draw firm conclusions from existing evidence. In addition, no information is available on the natural history of adenomyosis and no study has systematically evaluated its existence in adolescents. Copyright © 2014 Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.

  14. [Trauma & the reproductive lifecycle in women].

    Born, Leslie; Phillips, Shauna Dae; Steiner, Meir; Soares, Claudio N

    2005-10-01

    Women are at significantly higher risk for developing post-traumatic stress disorder (PTSD) than men, resulting in increased psychosocial burden and healthcare related costs. Recent research has shown complex interactions between the impact of traumatic experiences, and the reproductive lifecycle in women. For example, women suffering from premenstrual dysphoric disorder (PMDD) who also report a history of sexual or physical abuse are more likely to present with different neuroendocrine reactivity to stressors, when compared to premenstrual dysphoric disorder subjects without prior history of trauma or abuse or non-premenstrual dysphoric disorder subjects. In addition, women with a history of abuse or trauma may experience re-emergence of symptoms during pregnancy. Lastly, females who experience miscarriage may present with even higher prevalence rates of post-traumatic stress disorder symptoms. In this manuscript we examine the existing data on gender differences in post-traumatic stress disorder, with particular focus on psychological and physiological factors that might be relevant to the development of symptoms after exposure to traumatic events associated with the reproductive life cycle. Current options available for the treatment of such symptoms, including group and counselling therapies and debriefing are critically reviewed.

  15. Automation life-cycle cost model

    Gathmann, Thomas P.; Reeves, Arlinda J.; Cline, Rick; Henrion, Max; Ruokangas, Corinne

    1992-01-01

    The problem domain being addressed by this contractual effort can be summarized by the following list: Automation and Robotics (A&R) technologies appear to be viable alternatives to current, manual operations; Life-cycle cost models are typically judged with suspicion due to implicit assumptions and little associated documentation; and Uncertainty is a reality for increasingly complex problems and few models explicitly account for its affect on the solution space. The objectives for this effort range from the near-term (1-2 years) to far-term (3-5 years). In the near-term, the envisioned capabilities of the modeling tool are annotated. In addition, a framework is defined and developed in the Decision Modelling System (DEMOS) environment. Our approach is summarized as follows: Assess desirable capabilities (structure into near- and far-term); Identify useful existing models/data; Identify parameters for utility analysis; Define tool framework; Encode scenario thread for model validation; and Provide transition path for tool development. This report contains all relevant, technical progress made on this contractual effort.

  16. The limits of bioenergy for mitigating global lifecycle greenhouse gas emissions from fossil fuels.

    Staples, Mark; Malina, Robert; Barrett, Steven

    2017-01-01

    In this Article we quantify the optimal allocation and deployment of global bioenergy resources to offset fossil fuels in 2050. We find that bioenergy could reduce lifecycle emissions attributable to combustion-fired electricity and heat, and liquid transportation fuels, by a maximum of 4.9-38.7 Gt CO2e, or 9-68%, and that offsetting fossil fuel-fired electricity and heat with bioenergy is on average 1.6-3.9 times more effective for emissions mitigation than offsetting fossil fuelderived ...

  17. Housing Habits and Their Implications for Life-Cycle Consumption and Investment

    Kraft, Holger; Munk, Claus; Wagner, Sebastian

    We set up and solve a rich life-cycle model of household decisions involving consumption of both perishable goods and housing services, stochastic and unspanned labor income, stochastic house prices, home renting and owning, stock investments, and portfolio constraints. The model features habit...... formation for housing consumption, which leads to optimal decisions closer in line with empirical observations. Our model can explain (i) that stock investments are low or zero for many young agents and then gradually increasing over life, (ii) that the housing expenditure share is age- and wealth...

  18. Housing Habits and Their Implications for Life-cycle Consumption and Investment

    Kraft, Holger; Munk, Claus; Wagner, Sebastian

    2017-01-01

    We solve a rich life-cycle model of household decisions involving consumption of perishable goods and housing services, habit formation for housing consumption, stochastic labor income, stochastic house prices, home renting and owning, stock investments, and portfolio constraints. In line...... with empirical observations, the optimal decisions involve (i) stock investments that are low or zero for many young agents and then gradually increasing over life, (ii) an age- and wealth-dependent housing expenditure share, (iii) non-housing consumption being significantly more sensitive to wealth and income...

  19. System Evaluation and Life-Cycle Cost Analysis of a Commercial-Scale High-Temperature Electrolysis Hydrogen Production Plant

    Edwin A. Harvego; James E. O' Brien; Michael G. McKellar

    2012-11-01

    Results of a system evaluation and lifecycle cost analysis are presented for a commercial-scale high-temperature electrolysis (HTE) central hydrogen production plant. The plant design relies on grid electricity to power the electrolysis process and system components, and industrial natural gas to provide process heat. The HYSYS process analysis software was used to evaluate the reference central plant design capable of producing 50,000 kg/day of hydrogen. The HYSYS software performs mass and energy balances across all components to allow optimization of the design using a detailed process flow sheet and realistic operating conditions specified by the analyst. The lifecycle cost analysis was performed using the H2A analysis methodology developed by the Department of Energy (DOE) Hydrogen Program. This methodology utilizes Microsoft Excel spreadsheet analysis tools that require detailed plant performance information (obtained from HYSYS), along with financial and cost information to calculate lifecycle costs. The results of the lifecycle analyses indicate that for a 10% internal rate of return, a large central commercial-scale hydrogen production plant can produce 50,000 kg/day of hydrogen at an average cost of $2.68/kg. When the cost of carbon sequestration is taken into account, the average cost of hydrogen production increases by $0.40/kg to $3.08/kg.

  20. Optimal Portfolio Choice with Annuitization

    Koijen, R.S.J.; Nijman, T.E.; Werker, B.J.M.

    2006-01-01

    We study the optimal consumption and portfolio choice problem over an individual's life-cycle taking into account annuity risk at retirement. Optimally, the investor allocates wealth at retirement to nominal, inflation-linked, and variable annuities and conditions this choice on the state of the

  1. Diseño de ejercicio docente basado en el estudio comparativo de metodologías de optimización del mantenimiento // Design of docent exercise based on comparative study between maintenance optimization methodologies

    Antonio Torres - Valle

    2010-09-01

    Full Text Available La enseñanza basada en problemas constituye un paso importante en la educación de losingenieros. Partiendo del desarrollo de la enseñanza activa, el artículo presenta el diseño de unejercicio docente basado en el estudio comparativo de dos métodos de optimización delmantenimiento: categorización de equipos y mantenimiento centrado en la confiabilidad (RCM eninglés. La aplicación concluye con referencias comparativas de carácter técnico donde sedemuestra la superioridad del segundo método. Finalmente, se establecen recomendaciones para eldiseño técnico metodológico del ejercicio.Palabras claves: mantenimiento, optimización, categorización de equipos, mantenimiento centrado enla confiabilidad, enseñanza basada en problemas, ejercicio docente, recomendaciones metodológicas.__________________________________________________________________________AbstractThe problem based learning is an important step in the education of the engineers. Beginning fromthe development of the active learning the paper presents the design of docent exercise based oncomparative study between two maintenance optimization methodologies: Equipment Categorizationand Reliability Centered Maintenance (RCM. The application concluded with technical comparativereferences, where demonstrates the superiority of the second one. Some recommendations for thetechnical methodological design of exercise are establishes.Key words: maintenance, optimization, equipment categorization, reliability centered maintenanceproblem based learning, docent exercise, methodological recommendations.

  2. Optimal sizing method for stand-alone photovoltaic power systems

    Groumpos, P P; Papageorgiou, G

    1987-01-01

    The total life-cycle cost of stand-alone photovoltaic (SAPV) power systems is mathematically formulated. A new optimal sizing algorithm for the solar array and battery capacity is developed. The optimum value of a balancing parameter, M, for the optimal sizing of SAPV system components is derived. The proposed optimal sizing algorithm is used in an illustrative example, where a more economical life-cycle cost has bene obtained. The question of cost versus reliability is briefly discussed.

  3. Engineering Information Infrastructure for Product Lifecycle Managment

    Kimura, Fumihiko

    For proper management of total product life cycle, it is fundamentally important to systematize design and engineering information about product systems. For example, maintenance operation could be more efficiently performed, if appropriate parts design information is available at the maintenance site. Such information shall be available as an information infrastructure for various kinds of engineering operations, and it should be easily accessible during the whole product life cycle, such as transportation, marketing, usage, repair/upgrade, take-back and recycling/disposal. Different from the traditional engineering database, life cycle support information has several characteristic requirements, such as flexible extensibility, distributed architecture, multiple viewpoints, long-time archiving, and product usage information, etc. Basic approaches for managing engineering information infrastructure are investigated, and various information contents and associated life cycle applications are discussed.

  4. [Discussion on Quality Evaluation Method of Medical Device During Life-Cycle in Operation Based on the Analytic Hierarchy Process].

    Zheng, Caixian; Zheng, Kun; Shen, Yunming; Wu, Yunyun

    2016-01-01

    The content related to the quality during life-cycle in operation of medical device includes daily use, repair volume, preventive maintenance, quality control and adverse event monitoring. In view of this, the article aims at discussion on the quality evaluation method of medical devices during their life cycle in operation based on the Analytic Hierarchy Process (AHP). The presented method is proved to be effective by evaluating patient monitors as example. The method presented in can promote and guide the device quality control work, and it can provide valuable inputs to decisions about purchase of new device.

  5. Sharing product data of nuclear power plants across their lifecycles by utilizing a neutral model

    Mun, Duhwan [WIG Craft Research Division, Maritime and Ocean Engineering Research Institute, KORDI, 171 Jang-dong, Yuseong-gu, Daejeon 305-343 (Korea, Republic of)], E-mail: dhmun@moeri.re.kr; Hwang, Jinsang [Department of Mechanical Engineering, KAIST (Korea, Republic of)], E-mail: mars@icad.kaist.ac.kr; Han, Soonhung [Department of Mechanical Engineering, KAIST (Korea, Republic of)], E-mail: shhan@kaist.ac.kr; Seki, Hiroshi [Hitachi Research Laboratory, Hitachi, Ltd. (Japan)], E-mail: hiroshi.seki.mf@hitachi.com; Yang, Jeongsam [Industrial and Information Systems Engineering, Ajou University (Korea, Republic of)], E-mail: jyang@ajou.ac.kr

    2008-02-15

    Many public and private Korean organizations are involved during the lifecycle of a domestic nuclear power plant. Korea Plant Engineering Co. (KOPEC) participates in the design stage, Korea Hydraulic and Nuclear Power (KHNP) operates and manages all nuclear power plants in Korea, Doosan Heavy Industry and Construction Co. manufactures the main equipment, and a construction company constructs the plant. Even though each organization has its own digital data management system and obtains a certain level of automation, data sharing among organizations is poor. KHNP obtains drawings and technical specifications from KOPEC in the form of paper. This results in manual re-work of definitions, and errors can potentially occur in the process. In order to establish an information bridge between design and operation and maintenance (O and M) phases, a generic product model (GPM), a data model from Hitachi, is extended for constructing a neutral data warehouse and the Korean Nuclear Power Plant Information Sharing System (KNPISS) is implemented.

  6. Sharing product data of nuclear power plants across their lifecycles by utilizing a neutral model

    Mun, Duhwan; Hwang, Jinsang; Han, Soonhung; Seki, Hiroshi; Yang, Jeongsam

    2008-01-01

    Many public and private Korean organizations are involved during the lifecycle of a domestic nuclear power plant. Korea Plant Engineering Co. (KOPEC) participates in the design stage, Korea Hydraulic and Nuclear Power (KHNP) operates and manages all nuclear power plants in Korea, Doosan Heavy Industry and Construction Co. manufactures the main equipment, and a construction company constructs the plant. Even though each organization has its own digital data management system and obtains a certain level of automation, data sharing among organizations is poor. KHNP obtains drawings and technical specifications from KOPEC in the form of paper. This results in manual re-work of definitions, and errors can potentially occur in the process. In order to establish an information bridge between design and operation and maintenance (O and M) phases, a generic product model (GPM), a data model from Hitachi, is extended for constructing a neutral data warehouse and the Korean Nuclear Power Plant Information Sharing System (KNPISS) is implemented

  7. Pavement maintenance scheduling using genetic algorithms

    Yang, Chao; Remenyte-Prescott, Rasa; Andrews, John D.

    2015-01-01

    This paper presents a new pavement management system (PMS) to achieve the optimal pavement maintenance and rehabilitation (M&R) strategy for a highway network using genetic algorithms (GAs). Optimal M&R strategy is a set of pavement activities that both minimise the maintenance cost of a highway network and maximise the pavement condition of the road sections on the network during a certain planning period. NSGA-II, a multi-objective GA, is employed to perform pavement maintenance optimisatio...

  8. Life-cycle assessment of biodiesel versus petroleum diesel fuel

    Coulon, R.; Camobreco, V.; Sheehan, J.; Duffield, J.

    1995-01-01

    The US Department of Energy's Office of Transportation Technologies, DOE's National Renewable Energy Laboratory, the US Department of Agriculture's Office of Energy, and Ecobalance are carrying out a comprehensive Life-Cycle Assessment of soy-based diesel fuel (biodiesel) to quantify the environmental aspects of the cradle-to-grave production and use of biodiesel. The purpose of the project is to produce an analytical tool and database for use by industry and government decision makers involved in alternative fuel use and production. The study also includes a parallel effort to develop a life-cycle model for petroleum diesel fuel. The two models are used to compare the life-cycle energy and environmental implications of petroleum diesel and biodiesel derived from soybean. Several scenarios are studied, analyzing the influence of transportation distances, agricultural practice and allocation rules used. The project also includes effort to integrate spatial data into the inventory analysis and probabilistic uncertainty considerations into the impact assessment stage. Traditional life-cycle inventory analysis includes an aggregation process that eliminates spatial, temporal, and threshold information. This project will demonstrate an approach to life-cycle inventory analysis that retains spatial data for use in impact assessment. Explicit probabilistic treatment of uncertainty in impact assessment will take account of scientific uncertainties, and will attempt to identify the level of spatial detail that most efficiently reduces impact assessment uncertainties

  9. Combined application of Product Lifecycle and Software Configuration Management systems for ITER remote handling

    Muhammad, Ali; Esque, Salvador; Aha, Liisa; Mattila, Jouni; Siuko, Mikko; Vilenius, Matti; Jaervenpaeae, Jorma; Irving, Mike; Damiani, Carlo; Semeraro, Luigi

    2009-01-01

    The advantages of Product Lifecycle Management (PLM) systems are widely understood among the industry and hence a PLM system is already in use by International Thermonuclear Experimental Reactor (ITER) Organization (IO). However, with the increasing involvement of software in the development, the role of Software Configuration Management (SCM) systems have become equally important. The SCM systems can be useful to meet the higher demands on Safety Engineering (SE), Quality Assurance (QA), Validation and Verification (V and V) and Requirements Management (RM) of the developed software tools. In an experimental environment, such as ITER, the new remote handling requirements emerge frequently. This means the development of new tools or the modification of existing tools and the development of new remote handling procedures or the modification of existing remote handling procedures. PLM and SCM systems together can be of great advantage in the development and maintenance of such remote handling system. In this paper, we discuss how PLM and SCM systems can be integrated together and play their role during the development and maintenance of ITER remote handling system. We discuss the possibility to investigate such setup at DTP2 (Divertor Test Platform 2), which is the full scale mock-up facility to verify the ITER divertor remote handling and maintenance concepts.

  10. Managing the Virtual Machine Lifecycle of the CernVM Project

    Charalampidis, I; Blomer, J; Buncic, P; Harutyunyan, A; Larsen, D

    2012-01-01

    CernVM is a virtual software appliance designed to support the development cycle and provide a runtime environment for LHC applications. It consists of a minimal Linux distribution, a specially tuned file system designed to deliver application software on demand, and contextualization tools. The maintenance of these components involves a variety of different procedures and tools that cannot always connect with each other. Additionally, most of these procedures need to be performed frequently. Currently, in the CernVM project, every time we build a new virtual machine image, we have to perform the whole process manually, because of the heterogeneity of the tools involved. The overall process is error-prone and time-consuming. Therefore, to simplify and aid this continuous maintenance process, we are developing a framework that combines these virtually unrelated tools with a single, coherent interface. To do so, we identified all the involved procedures and their tools, tracked their dependencies and organized them into logical groups (e.g. build, test, instantiate). These groups define the procedures that are performed throughout the lifetime of a virtual machine. In this paper we describe the Virtual Machine Lifecycle and the framework we developed (iAgent) in order to simplify the maintenance process.

  11. Regulation of the hematopoietic stem cell lifecycle by the endothelial niche.

    Ramalingam, Pradeep; Poulos, Michael G; Butler, Jason M

    2017-07-01

    Hematopoietic stem cells (HSCs) predominantly reside either in direct contact or in close proximity to the vascular endothelium throughout their lifespan. From the moment of HSC embryonic specification from hemogenic endothelium, endothelial cells (ECs) act as a critical cellular-hub that regulates a vast repertoire of biological processes crucial for HSC maintenance throughout its lifespan. In this review, we will discuss recent findings in endothelial niche-mediated regulation of HSC function during development, aging and regenerative conditions. Studies employing genetic vascular models have unequivocally confirmed that ECs provide the essential instructive cues for HSC emergence during embryonic development as well as adult HSC maintenance during homeostasis and regeneration. Aging of ECs may impair their ability to maintain HSC function contributing to the development of aging-associated hematopoietic deficiencies. These findings have opened up new avenues to explore the therapeutic application of ECs. ECs can be adapted to serve as an instructive platform to expand bona fide HSCs and also utilized as a cellular therapy to promote regeneration of the hematopoietic system following myelosuppressive and myeloablative injuries. ECs provide a fertile niche for maintenance of functional HSCs throughout their lifecycle. An improved understanding of the EC-HSC cross-talk will pave the way for development of EC-directed strategies for improving HSC function during aging.

  12. Debris-flow risk analysis in a managed torrent based on a stochastic life-cycle performance

    Ballesteros Cánovas, J.A.; Stoffel, M.; Corona, C.; Schraml, K.; Gobiet, A.; Tani, S.; Sinabell, F.; Fuchs, S.; Kaitna, R.

    2016-01-01

    Two key factors can affect the functional ability of protection structures in mountains torrents, namely (i) infrastructure maintenance of existing infrastructures (as a majority of existing works is in the second half of their life cycle), and (ii) changes in debris-flow activity as a result of ongoing and expected future climatic changes. Here, we explore the applicability of a stochastic life-cycle performance to assess debris-flow risk in the heavily managed Wartschenbach torrent (Lienz region, Austria) and to quantify associated, expected economic losses. We do so by considering maintenance costs to restore infrastructure in the aftermath of debris-flow events as well as by assessing the probability of check dam failure (e.g., as a result of overload). Our analysis comprises two different management strategies as well as three scenarios defining future changes in debris-flow activity resulting from climatic changes. At the study site, an average debris-flow frequency of 21 events per decade was observed for the period 1950–2000; activity at the site is projected to change by + 38% to − 33%, according to the climate scenario used. Comparison of the different management alternatives suggests that the current mitigation strategy will allow to reduce expected damage to infrastructure and population almost fully (89%). However, to guarantee a comparable level of safety, maintenance costs is expected to increase by 57–63%, with an increase of maintenance costs by ca. 50% for each intervention. Our analysis therefore also highlights the importance of taking maintenance costs into account for risk assessments realized in managed torrent systems, as they result both from progressive and event-related deteriorations. We conclude that the stochastic life-cycle performance adopted in this study represents indeed an integrated approach to assess the long-term effects and costs of prevention structures in managed torrents. - Highlights: • Debris flows are considered

  13. Debris-flow risk analysis in a managed torrent based on a stochastic life-cycle performance

    Ballesteros Cánovas, J.A., E-mail: juan.ballesteros@dendrolab.ch [Dendrolab.ch. Institute for Geological Sciences, University of Bern, Baltzerstrasse 1 + 3, CH-3012 Bern (Switzerland); Climate Change an Climate Impacts (C3i) Institute for Environmental Sciences, University of Geneva, 66 Boulevard Carl-Vogt, CH-1205 Geneva (Switzerland); Stoffel, M. [Dendrolab.ch. Institute for Geological Sciences, University of Bern, Baltzerstrasse 1 + 3, CH-3012 Bern (Switzerland); Climate Change an Climate Impacts (C3i) Institute for Environmental Sciences, University of Geneva, 66 Boulevard Carl-Vogt, CH-1205 Geneva (Switzerland); Department of Earth Sciences, University of Geneva, 13 rue des Maraîchers, CH-1205 Geneva (Switzerland); Corona, C. [Centre National de la Recherche Scientifique (CNRS) UMR6042 Geolab, 4 rue Ledru, F-63057 Clermont-Ferrand Cedex (France); Schraml, K. [Institute for Alpine Hazards, University of Natural Resources and Life Sciences, Vienna (BOKU), A-1190 Vienna (Austria); Gobiet, A. [University of Graz, Wegener Center for Climate and Global Change (WegCenter), A-8010 Graz (Austria); Central Office for Meteorology and Geodynamics (ZAMG), A-1190 Vienna (Austria); Tani, S. [University of Graz, Wegener Center for Climate and Global Change (WegCenter), A-8010 Graz (Austria); Sinabell, F. [Austrian Institute of Economic Research, A-1030 Vienna (Austria); Fuchs, S.; Kaitna, R. [Institute for Alpine Hazards, University of Natural Resources and Life Sciences, Vienna (BOKU), A-1190 Vienna (Austria)

    2016-07-01

    Two key factors can affect the functional ability of protection structures in mountains torrents, namely (i) infrastructure maintenance of existing infrastructures (as a majority of existing works is in the second half of their life cycle), and (ii) changes in debris-flow activity as a result of ongoing and expected future climatic changes. Here, we explore the applicability of a stochastic life-cycle performance to assess debris-flow risk in the heavily managed Wartschenbach torrent (Lienz region, Austria) and to quantify associated, expected economic losses. We do so by considering maintenance costs to restore infrastructure in the aftermath of debris-flow events as well as by assessing the probability of check dam failure (e.g., as a result of overload). Our analysis comprises two different management strategies as well as three scenarios defining future changes in debris-flow activity resulting from climatic changes. At the study site, an average debris-flow frequency of 21 events per decade was observed for the period 1950–2000; activity at the site is projected to change by + 38% to − 33%, according to the climate scenario used. Comparison of the different management alternatives suggests that the current mitigation strategy will allow to reduce expected damage to infrastructure and population almost fully (89%). However, to guarantee a comparable level of safety, maintenance costs is expected to increase by 57–63%, with an increase of maintenance costs by ca. 50% for each intervention. Our analysis therefore also highlights the importance of taking maintenance costs into account for risk assessments realized in managed torrent systems, as they result both from progressive and event-related deteriorations. We conclude that the stochastic life-cycle performance adopted in this study represents indeed an integrated approach to assess the long-term effects and costs of prevention structures in managed torrents. - Highlights: • Debris flows are considered

  14. Supporting the scientific lifecycle through cloud services

    Gensch, S.; Klump, J. F.; Bertelmann, R.; Braune, C.

    2014-12-01

    Cloud computing has made resources and applications available for numerous use cases ranging from business processes in the private sector to scientific applications. Developers have created tools for data management, collaborative writing, social networking, data access and visualization, project management and many more; either for free or as paid premium services with additional or extended features. Scientists have begun to incorporate tools that fit their needs into their daily work. To satisfy specialized needs, some cloud applications specifically address the needs of scientists for sharing research data, literature search, laboratory documentation, or data visualization. Cloud services may vary in extent, user coverage, and inter-service integration and are also at risk of being abandonend or changed by the service providers making changes to their business model, or leaving the field entirely.Within the project Academic Enterprise Cloud we examine cloud based services that support the research lifecycle, using feature models to describe key properties in the areas of infrastructure and service provision, compliance to legal regulations, and data curation. Emphasis is put on the term Enterprise as to establish an academic cloud service provider infrastructure that satisfies demands of the research community through continious provision across the whole cloud stack. This could enable the research community to be independent from service providers regarding changes to terms of service and ensuring full control of its extent and usage. This shift towards a self-empowered scientific cloud provider infrastructure and its community raises implications about feasability of provision and overall costs. Legal aspects and licensing issues have to be considered, when moving data into cloud services, especially when personal data is involved.Educating researchers about cloud based tools is important to help in the transition towards effective and safe use. Scientists

  15. Advanced Technology Lifecycle Analysis System (ATLAS)

    O'Neil, Daniel A.; Mankins, John C.

    2004-01-01

    Developing credible mass and cost estimates for space exploration and development architectures require multidisciplinary analysis based on physics calculations, and parametric estimates derived from historical systems. Within the National Aeronautics and Space Administration (NASA), concurrent engineering environment (CEE) activities integrate discipline oriented analysis tools through a computer network and accumulate the results of a multidisciplinary analysis team via a centralized database or spreadsheet Each minute of a design and analysis study within a concurrent engineering environment is expensive due the size of the team and supporting equipment The Advanced Technology Lifecycle Analysis System (ATLAS) reduces the cost of architecture analysis by capturing the knowledge of discipline experts into system oriented spreadsheet models. A framework with a user interface presents a library of system models to an architecture analyst. The analyst selects models of launchers, in-space transportation systems, and excursion vehicles, as well as space and surface infrastructure such as propellant depots, habitats, and solar power satellites. After assembling the architecture from the selected models, the analyst can create a campaign comprised of missions spanning several years. The ATLAS controller passes analyst specified parameters to the models and data among the models. An integrator workbook calls a history based parametric analysis cost model to determine the costs. Also, the integrator estimates the flight rates, launched masses, and architecture benefits over the years of the campaign. An accumulator workbook presents the analytical results in a series of bar graphs. In no way does ATLAS compete with a CEE; instead, ATLAS complements a CEE by ensuring that the time of the experts is well spent Using ATLAS, an architecture analyst can perform technology sensitivity analysis, study many scenarios, and see the impact of design decisions. When the analyst is

  16. Value maximizing maintenance policies under general repair

    Marais, Karen B.

    2013-01-01

    One class of maintenance optimization problems considers the notion of general repair maintenance policies where systems are repaired or replaced on failure. In each case the optimality is based on minimizing the total maintenance cost of the system. These cost-centric optimizations ignore the value dimension of maintenance and can lead to maintenance strategies that do not maximize system value. This paper applies these ideas to the general repair optimization problem using a semi-Markov decision process, discounted cash flow techniques, and dynamic programming to identify the value-optimal actions for any given time and system condition. The impact of several parameters on maintenance strategy, such as operating cost and revenue, system failure characteristics, repair and replacement costs, and the planning time horizon, is explored. This approach provides a quantitative basis on which to base maintenance strategy decisions that contribute to system value. These decisions are different from those suggested by traditional cost-based approaches. The results show (1) how the optimal action for a given time and condition changes as replacement and repair costs change, and identifies the point at which these costs become too high for profitable system operation; (2) that for shorter planning horizons it is better to repair, since there is no time to reap the benefits of increased operating profit and reliability; (3) how the value-optimal maintenance policy is affected by the system's failure characteristics, and hence whether it is worthwhile to invest in higher reliability; and (4) the impact of the repair level on the optimal maintenance policy. -- Highlights: •Provides a quantitative basis for maintenance strategy decisions that contribute to system value. •Shows how the optimal action for a given condition changes as replacement and repair costs change. •Shows how the optimal policy is affected by the system's failure characteristics. •Shows when it is

  17. The lifecycle approach as a driver for innovative power contracting; Der Lifecycle-Ansatz als Treiber fuer innovatives Energie-Contracting

    Gayer, Alfred [RWE Energiedienstleistungen GmbH (Germany)

    2011-07-01

    The sensible and efficient use of energy raises more and more the general awareness. The efficiency of projects will be influenced not only by the replacement of existing technology, but also mainly by the general conception of the design of decentralized energy supplies. The integration of waste heat from production-related processes as well as the use of all forms of energy such as electricity, heat, refrigeration and compressed air to meet the customer needs in a comprehensive energy plan increase the complexity and significantly the efficiencies. In the implementation of such projects the contracting is becoming increasingly important because the future gains in efficiency are taken into account directly. Contracting projects include the traditional total-cost-of-ownership approach (lifecycle approach). This approach considers the investment costs as well as the consequential costs of a project and shows how to optimize the total cost.

  18. Reliability analysis and risk-based methods for planning of operation & maintenance of offshore wind turbines

    Sørensen, John Dalsgaard

    2017-01-01

    for extreme and fatigue limit states are presented. Operation & Maintenance planning often follows corrective and preventive strategies based on information from condition monitoring and structural health monitoring systems. A reliability- and risk-based approach is presented where a life-cycle approach...

  19. Analysis within the systems development life-cycle

    Rock-Evans, Rosemary

    1987-01-01

    Analysis within the Systems Development Life-Cycle: Book 4, Activity Analysis-The Methods describes the techniques and concepts for carrying out activity analysis within the systems development life-cycle. Reference is made to the deliverables of data analysis and more than one method of analysis, each a viable alternative to the other, are discussed. The """"bottom-up"""" and """"top-down"""" methods are highlighted. Comprised of seven chapters, this book illustrates how dependent data and activities are on each other. This point is especially brought home when the task of inventing new busin

  20. Analysis within the systems development life-cycle

    Rock-Evans, Rosemary

    1987-01-01

    Analysis within the Systems Development Life-Cycle: Book 2, Data Analysis-The Methods describes the methods for carrying out data analysis within the systems development life-cycle and demonstrates how the results of fact gathering can be used to produce and verify the analysis deliverables. A number of alternative methods of analysis other than normalization are suggested. Comprised of seven chapters, this book shows the tasks to be carried out in the logical order of progression-preparation, collection, analysis of the existing system (which comprises the tasks of synthesis, verification, an

  1. Analysis within the systems development life-cycle

    Rock-Evans, Rosemary

    1987-01-01

    Analysis within the Systems Development Life-Cycle: Book 1, Data Analysis-The Deliverables provides a comprehensive treatment of data analysis within the systems development life-cycle and all the deliverables that need to be collected in analysis. The purpose of deliverables is explained and a number of alternative ways of collecting them are discussed. This book is comprised of five chapters and begins with an overview of what """"analysis"""" actually means, with particular reference to tasks such as hardware planning and software evaluation and where they fit into the overall cycle. The ne

  2. Maintenance and environmental qualification

    Martin, R.S.; Austin, D.G.

    1995-01-01

    The design of today's nuclear generating plants involves many detailed design considerations. This includes comprehensive look at aging effects on plant components over their expected lifetimes. This is important to ensuring that the plant operates safely throughout its life. The effects of aging are required to be documented in detail in today's designs. This documentation provides assurance that safe operating conditions are maintained throughout the station life cycle. This requirement is analogous to the longer standing requirement to ensure pressure boundary integrity. The pressure boundary integrity requirement has existed in the industry since its inception. The subject of plant aging effects and the maintenance of functionality is known as Environmental Qualification (EQ). This paper will attempt to explain the wisdom of EQ and the potential for optimizing maintenance activities (to move from reactive to proactive activities), within the context of the overall maintenance program. It is the author's intent to encourage the active involvement of maintenance professionals in the effective implementation of the ongoing EQ program so that the benefits are maximized

  3. Opportune maintenance and predictive maintenance decision support

    Thomas , Edouard; Levrat , Eric; Iung , Benoît; Cocheteux , Pierre

    2009-01-01

    International audience; Conventional maintenance strategies on a single component are being phased out in favour of more predictive maintenance actions. These new kinds of actions are performed in order to control the global performances of the whole industrial system. They are anticipative in nature, which allows a maintenance expert to consider non-already-planned maintenance actions. Two questions naturally emerge: when to perform a predictive maintenance action; how a maintenance expert c...

  4. A proactive condition-based maintenance strategy with both perfect and imperfect maintenance actions

    Do, Phuc; Voisin, Alexandre; Levrat, Eric; Iung, Benoit

    2015-01-01

    This paper deals with a proactive condition-based maintenance (CBM) considering both perfect and imperfect maintenance actions for a deteriorating system. Perfect maintenance actions restore completely the system to the ‘as good as new’ state. Their related cost are however often high. The first objective of the paper is to investigate the impacts of imperfect maintenance actions. In fact, both positive and negative impacts are considered. Positive impact means that the imperfect maintenance cost is usually low. Negative impact implies that (i) the imperfect maintenance restores a system to a state between good-as-new and bad-as-old and (ii) each imperfect preventive action may accelerate the speed of the system's deterioration process. The second objective of the paper is to propose an adaptive maintenance policy which can help to select optimally maintenance actions (perfect or imperfect actions), if needed, at each inspection time. Moreover, the time interval between two successive inspection points is determined according to a remaining useful life (RUL) based-inspection policy. To illustrate the use of the proposed maintenance policy, a numerical example finally is introduced. - Highlights: • A new imperfect maintenance model for deterioration system is proposed. • Both positive and negative impacts of an imperfect maintenance action are investigated. • An adaptive condition-based maintenance policy is introduced. • The optimal number of useful imperfect maintenance actions for each life cycle is optimally provided

  5. Network maintenance

    GS Department

    2009-01-01

    A site-wide network maintenance operation has been scheduled for Saturday 28 February. Most of the network devices of the general purpose network will be upgraded to a newer software version, in order to improve our network monitoring capabilities. This will result in a series of short (2-5 minutes) random interruptions everywhere on the CERN sites throughout the day. This upgrade will not affect the Computer Centre itself, Building 613, the Technical Network and the LHC experiments, dedicated networks at the pits. For further details of this intervention, please contact Netops by phone 74927 or e-mail mailto:Netops@cern.ch. IT/CS Group

  6. Network maintenance

    IT Department

    2009-01-01

    A site wide network maintenance has been scheduled for Saturday 28 February. Most of the network devices of the General Purpose network will be upgraded to a newer software version, in order to improve our network monitoring capabilities. This will result in a series of short (2-5 minutes) random interruptions everywhere on the CERN sites along this day. This upgrade will not affect: the Computer centre itself, building 613, the Technical Network and the LHC experiments dedicated networks at the pits. Should you need more details on this intervention, please contact Netops by phone 74927 or email mailto:Netops@cern.ch. IT/CS Group

  7. Approach on Lifecycles on Research Environment and Analysis Based on Systems Engineering (SE)

    Lintala , Marja; Ovtcharova , Jivka; Bonnal , Pierre

    2012-01-01

    Part 8: Formalization for PLM; International audience; In recent years, researchers and industrial communities have been increasingly interested in Product Lifecycle Management (PLM); hence the product lifecycles have received considerable attention. The general features of the lifecycles are well known, however the special character of the equipment in research environment: the particularly long life, experimental character, complexity and interdisciplinary, are still not completely understo...

  8. Planning factors for developing an enterprise-wide picture archiving and communication system maintenance program.

    Staley, S; Romlein, J; Chacko, A K; Wider, R

    2000-05-01

    Picture archiving and communication system (PACS) maintenance on an individual site basis has historically been a complex and costly challenge. With the advent of enterprise-wide PACS projects such as the Virtual Radiology Environment (VRE) project, the challenge of a maintenance program with even more complexities has presented itself. The approach of the project management team for the VRE project is not one of reactive maintenance, but one of highly proactive planning and negotiations, in hopes of capitalizing on the economies of scale of an enterprise-wide PACS maintenance program. A proactive maintenance program is one aspect of life-cycle management. As with any capital acquisition, life-cycle management may be used to manage the specific project aspects related to PACS. The purpose of an enterprise-wide warranty and maintenance life-cycle management approach is to maintain PACS at its maximum operational efficiency and utilization levels through a flexible, shared, yet symbiotic relationship between local, regional, and vendor resources. These goals include providing maximum operational performance levels on a local, regional, and enterprise basis, while maintaining acceptable costs and resource utilization levels. This goal must be achieved without negatively impacting point of care activities, regardless of changes to the clinical business environment.

  9. Life-cycle stages of Dinophysis acuminata (Dinophyceae) in the ...

    Despite many observations of different life-cycle stages of Dinophysis species, the complete life history of the genus is still unknown owing to the difficulties encountered in culturing these species. The seasonal distribution of D. acuminata was followed at two offshore stations in the brackish Baltic Sea by means of in situ ...

  10. A full lifecycle bioenergetic model for bluefin tuna.

    Jusup, M.; Klanjscek, T.; Matsuda, H.; Kooijman, S.A.L.M.

    2011-01-01

    We formulated a full lifecycle bioenergetic model for bluefin tuna relying on the principles of Dynamic Energy Budget theory. Traditional bioenergetic models in fish research deduce energy input and utilization from observed growth and reproduction. In contrast, our model predicts growth and

  11. Life-cycle of the European compost worm Dendrobaena veneta ...

    1990-06-05

    Jun 5, 1990 ... that this species does have potential to combat organic waste problems. The complete life-cycle of D. veneta has not been documented yeL We therefore included this ... in plastic containers with gauze lids. Fifty grams of the stabilized culture medium per wonn was added when the experiment was started.

  12. Comparative Life-Cycle Cost Analysis Of Solar Photovoltaic Power ...

    Comparative Life-Cycle Cost Analysis Of Solar Photovoltaic Power System And Diesel Generator System For Remote Residential Application In Nigeria. ... like capital cost, and diesel fuel costs are varied. The results show the photovoltaic system to be more cost-effective at low-power ranges of electrical energy supply.

  13. An introduction to Life-cycle Thinking and Management

    Remmen, Arne

    This booklet descibes how enterprises can begin developing cleaner products based on a life-cycle perspective. It focuses on a simple approach to preventive environmental initiatives, where enterprises can begin at a level that matches their ambitions and their preconditions. The report is aimed...... at enterprises that, irregardless of size or sector, are interested in reducing environmental impacts from their products....

  14. The Lifecycle of Trust in Educational Leadership: An Ecological Perspective

    Kutsyuruba, Benjamin; Walker, Keith

    2015-01-01

    As establishing and fostering trust are imperative activities for school leaders, cognizance of the fundamental importance of trust is essential for the leader's moral agency and ethical decision-making. In this article, we use an ecological perspective to uncover the dynamics of the lifecycle of trust as evident from extant literature on…

  15. Transport biofuels - a life-cycle assessment approach

    Reijnders, L.

    2008-01-01

    Life-cycle studies of the currently dominant transport biofuels (bioethanol made from starch or sugar and biodiesel made from vegetable oil) show that solar energy conversion efficiency is relatively poor if compared with solar cells and that such biofuels tend to do worse than conventional fossil

  16. Lifecycle1: Flute (piccolo), oboe, clarinet (bass clarinet), bassoon ...

    Lifecycle1: Flute (piccolo), oboe, clarinet (bass clarinet), bassoon, horn, 2 percussionists, 2 violins and cello, Xhosa vocal ensemble and indigenous instruments. J Zaidel-Rudoulph. Abstract. No Abstract Journal for the Musical Arts in Africa Vol. 3 2007: pp. 80-81. Full Text: EMAIL FULL TEXT EMAIL FULL TEXT

  17. Life-Cycle Inventory Analysis of Manufacturing Redwood Decking

    Richard D. Bergman; Han-Sup Han; Elaine Oneil; Ivan L. Eastin

    2012-01-01

    Green building has become increasingly important. Therefore, consumers and builders often take into account the environmental attributes of a building material. This study determined the environmental attributes associated with manufacturing 38-mm × 138-mm (nominal 2 × 6) redwood decking in northern California using the life-cycle inventory method. Primary data...

  18. Life-cycle air emissions from PV power systems

    Watt, M.E.; Johnson, A.J.; Outhred, H.R.; Ellis, M.

    1998-01-01

    This paper addresses the air emission of grid supply versus grid-connected and off-grid photovoltaic power generation, using the framework of life-cycle assessment, in the contents of rural household energy supply in Australia. Emissions of carbon dioxide, sulphur dioxde and nitrous oxides are calculated for the three life-cycle stages of manufacture, use and disposal. Sensitivities to materials and data inputs, as well as to component efficiencies, lifetimes and sizing are discussed. For each supply option, demand management options, including insulation and appliance choice, and the substitution of solar heating or bottled gas for electricity are considered. The best option in all cases, in terms of life-cycle air emissions, is a grid-connected photovoltaic system used to supply an energy-efficient household with a mix of solar, gas and electric appliances. However, in financial terms, with current Australian energy prices, this option represents a high capital and life-cycle costs. Additionally, for the grid options, electricity costs do not significantly disadvantage the high demand scenarios. Both results provide a clear illustration of current Australian energy-pricing policies being in conflict with long-term environmental sustainability. (Author)

  19. FileNet's BPM life-cycle support

    Netjes, M.; Reijers, H.A.; Aalst, van der W.M.P.

    2006-01-01

    Business Process Management (BPM) systems provide a broad range of facilities to enact and manage operational business processes. Ideally, these systems should provide support for the complete BPM life-cycle: (re)design, configuration, execution, control, and diagnosis of processes. In the research

  20. Life-cycle of the European compost worm Dendrobaena veneta ...

    The life-cycle of Dendrobaena veneta was studied to assess the potential of this species in vermiculture. The development, growth and reproduction were investigated by rearing worms at 25°C on urine-free cattle manure with a moisture content of 80% over a period of 200 days. It was found that cocoons are produced at a ...

  1. Product Lifecycle Management and the Quest for Sustainable Space Exploration Solutions

    Caruso, Pamela W.; Dumbacher, Daniel L.

    2010-01-01

    less hands-on labor needed for processing and troubleshooting. Sustainable space exploration solutions demand that all lifecycle phases be optimized. Adopting PLM, which has been used by the automotive industry for many years, for aerospace applications provides a foundation for strong, disciplined systems engineering and accountable return on investment by making lifecycle considerations variables in an iterative decision-making process. This paper combines the perspectives of the founding father of PLM, along with the experience of Engineering leaders who are implementing these processes and practices real-time. As the nation moves from an industrial-based society to one where information is a valued commodity, future NASA programs and projects will benefit from the experience being gained today for the exploration missions of tomorrow.

  2. Towards real energy economics: Energy policy driven by life-cycle carbon emission

    Kenny, R.; Law, C.; Pearce, J.M.

    2010-01-01

    Alternative energy technologies (AETs) have emerged as a solution to the challenge of simultaneously meeting rising electricity demand while reducing carbon emissions. However, as all AETs are responsible for some greenhouse gas (GHG) emissions during their construction, carbon emission 'Ponzi Schemes' are currently possible, wherein an AET industry expands so quickly that the GHG emissions prevented by a given technology are negated to fabricate the next wave of AET deployment. In an era where there are physical constraints to the GHG emissions the climate can sustain in the short term this may be unacceptable. To provide quantitative solutions to this problem, this paper introduces the concept of dynamic carbon life-cycle analyses, which generate carbon-neutral growth rates. These conceptual tools become increasingly important as the world transitions to a low-carbon economy by reducing fossil fuel combustion. In choosing this method of evaluation it was possible to focus uniquely on reducing carbon emissions to the recommended levels by outlining the most carbon-effective approach to climate change mitigation. The results of using dynamic life-cycle analysis provide policy makers with standardized information that will drive the optimization of electricity generation for effective climate change mitigation.

  3. Life-cycle implications and supply chain logistics of electric vehicle battery recycling in California

    Hendrickson, Thomas P.; Kavvada, Olga; Shah, Nihar; Sathre, Roger; Scown, Corinne D.

    2015-01-01

    Plug-in electric vehicle (PEV) use in the United States (US) has doubled in recent years and is projected to continue increasing rapidly. This is especially true in California, which makes up nearly one-third of the current US PEV market. Planning and constructing the necessary infrastructure to support this projected increase requires insight into the optimal strategies for PEV battery recycling. Utilizing life-cycle perspectives in evaluating these supply chain networks is essential in fully understanding the environmental consequences of this infrastructure expansion. This study combined life-cycle assessment and geographic information systems (GIS) to analyze the energy, greenhouse gas (GHG), water use, and criteria air pollutant implications of end-of-life infrastructure networks for lithium-ion batteries (LIBs) in California. Multiple end-of-life scenarios were assessed, including hydrometallurgical and pyrometallurgical recycling processes. Using economic and environmental criteria, GIS modeling revealed optimal locations for battery dismantling and recycling facilities for in-state and out-of-state recycling scenarios. Results show that economic return on investment is likely to diminish if more than two in-state dismantling facilities are constructed. Using rail as well as truck transportation can substantially reduce transportation-related GHG emissions (23-45%) for both in-state and out-of-state recycling scenarios. The results revealed that material recovery from pyrometallurgy can offset environmental burdens associated with LIB production, namely a 6-56% reduction in primary energy demand and 23% reduction in GHG emissions, when compared to virgin production. Incorporating human health damages from air emissions into the model indicated that Los Angeles and Kern Counties are most at risk in the infrastructure scale-up for in-state recycling due to their population density and proximity to the optimal location.

  4. Life-cycle implications and supply chain logistics of electric vehicle battery recycling in California

    Hendrickson, Thomas P; Kavvada, Olga; Shah, Nihar; Sathre, Roger; D Scown, Corinne

    2015-01-01

    Plug-in electric vehicle (PEV) use in the United States (US) has doubled in recent years and is projected to continue increasing rapidly. This is especially true in California, which makes up nearly one-third of the current US PEV market. Planning and constructing the necessary infrastructure to support this projected increase requires insight into the optimal strategies for PEV battery recycling. Utilizing life-cycle perspectives in evaluating these supply chain networks is essential in fully understanding the environmental consequences of this infrastructure expansion. This study combined life-cycle assessment and geographic information systems (GIS) to analyze the energy, greenhouse gas (GHG), water use, and criteria air pollutant implications of end-of-life infrastructure networks for lithium-ion batteries (LIBs) in California. Multiple end-of-life scenarios were assessed, including hydrometallurgical and pyrometallurgical recycling processes. Using economic and environmental criteria, GIS modeling revealed optimal locations for battery dismantling and recycling facilities for in-state and out-of-state recycling scenarios. Results show that economic return on investment is likely to diminish if more than two in-state dismantling facilities are constructed. Using rail as well as truck transportation can substantially reduce transportation-related GHG emissions (23–45%) for both in-state and out-of-state recycling scenarios. The results revealed that material recovery from pyrometallurgy can offset environmental burdens associated with LIB production, namely a 6–56% reduction in primary energy demand and 23% reduction in GHG emissions, when compared to virgin production. Incorporating human health damages from air emissions into the model indicated that Los Angeles and Kern Counties are most at risk in the infrastructure scale-up for in-state recycling due to their population density and proximity to the optimal location. (letter)

  5. Optimal inspection planning for onshore pipelines subject to external corrosion

    Gomes, Wellison J.S.; Beck, André T.; Haukaas, Terje

    2013-01-01

    Continuous operation of pipeline systems involves significant expenditures in inspection and maintenance activities. The cost-effective safety management of such systems involves allocating the optimal amount of resources to inspection and maintenance activities, in order to control risks (expected costs of failure). In this context, this article addresses the optimal inspection planning for onshore pipelines subject to external corrosion. The investigation addresses a challenging problem of practical relevance, and strives for using the best available models to describe random corrosion growth and the relevant limit state functions. A single pipeline segment is considered in this paper. Expected numbers of failures and repairs are evaluated by Monte Carlo sampling, and a novel procedure is employed to evaluate sensitivities of the objective function with respect to design parameters. This procedure is shown to be accurate and more efficient than finite differences. The optimum inspection interval is found for an example problem, and the robustness of this optimum to the assumed inspection and failure costs is investigated. It is shown that optimum total expected costs found herein are not highly sensitive to the assumed costs of inspection and failure. -- Highlights: • Inspection, repair and failure costs of pipeline systems considered. • Optimum inspection schedule (OIS) obtained by minimizing total expected life-cycle costs. • Robustness of OIS evaluated w.r.t. estimated costs of inspection and failure. • Accurate non-conservative models of corrosion growth employed

  6. TRANSCRIPTOME ANALYSES REVEAL DIFFERENTIAL GENE EXPRESSION PATTERNS BETWEEN THE LIFE-CYCLE STAGES OF EMILIANIA HUXLEYI (HAPTOPHYTA) AND REFLECT SPECIALIZATION TO DIFFERENT ECOLOGICAL NICHES(1).

    Rokitta, Sebastian D; de Nooijer, Lennart J; Trimborn, Scarlett; de Vargas, Colomban; Rost, Björn; John, Uwe

    2011-08-01

    Coccolithophores, especially the abundant, cosmopolitan species Emiliania huxleyi (Lohmann) W. W. Hay et H. P. Mohler, are one of the main driving forces of the oceanic carbonate pump and contribute significantly to global carbon cycling, due to their ability to calcify. A recent study indicates that termination of diploid blooms by viral infection induces life-cycle transition, and speculation has arisen about the role of the haploid, noncalcifying stage in coccolithophore ecology. To explore gene expression patterns in both life-cycle stages, haploid and diploid cells of E. huxleyi (RCC 1217 and RCC 1216) were acclimated to limiting and saturating photon flux densities. Transcriptome analyses were performed to assess differential genomic expression related to different ploidy levels and acclimation light intensities. Analyses indicated that life-cycle stages exhibit different properties of regulating genome expression (e.g., pronounced gene activation and gene silencing in the diploid stage), proteome maintenance (e.g., increased turnover of proteins in the haploid stage), as well as metabolic processing (e.g., pronounced primary metabolism and motility in the haploid stage and calcification in the diploid stage). Furthermore, higher abundances of transcripts related to endocytotic and digestive machinery were observed in the diploid stage. A qualitative feeding experiment indicated that both life-cycle stages are capable of particle uptake (0.5 μm diameter) in late-stationary growth phase. Results showed that the two life-cycle stages represent functionally distinct entities that are evolutionarily shaped to thrive in the environment they typically inhabit. © 2011 Phycological Society of America.

  7. Machinery prognostics and prognosis oriented maintenance management

    Yan, Jihong

    2014-01-01

    This book gives a complete presentatin of the basic essentials of machinery prognostics and prognosis oriented maintenance management, and takes a look at the cutting-edge discipline of intelligent failure prognosis technologies for condition-based maintenance.  Latest research results and application methods are introduced for signal processing, reliability moelling, deterioration evaluation, residual life prediction and maintenance-optimization as well as applications of these methods.

  8. Single-tooth implant restorations in the esthetic zone--contemporary concepts for optimization and maintenance of soft tissue esthetics in the replacement of failing teeth in compromised sites.

    Mankoo, Tidu

    2007-01-01

    In recent years, implant dentistry has undergone a profound shift in emphasis. The focus evolved first from a surgically driven approach to a prosthetically driven approach and now to a more biologically driven approach with the goal of optimizing and maintaining esthetics. While traditional implant protocols are well established for management of implants placed in healed edentulous sites, the data available offer little clarity on the factors and procedures for long-term esthetic success, particularly in terms of maintained stable soft tissue outcomes around implant restorations in the esthetic zone. Unfortunately, the 90%+ success rates indicated in most studies of dental implant systems today do not represent the success of the esthetic outcome. This has created a demand--certainly among clinicians in private practice focused on the ongoing maintenance of esthetic outcomes--for clear treatment protocols to achieve esthetic results that are not only predictable and consistent but that can withstand the test of time.

  9. Life-Cycle Consumption and Children

    Jørgensen, Thomas Høgholm

    2017-01-01

    I estimate by maximum likelihood a dynamic model of optimal intertemporal allocation of consumption in the presence of children using high-quality Danish longitudinal data. The number and age of all children can affect the marginal utility of consumption while income uncertainty, credit constraints...... and postretirement motives also influence household behaviour. While I estimate that children have a surprisingly small effect on the marginal utility of non-durable consumption, data simulated from the estimated model replicates similar correlations between log consumption growth and changing household composition...... as found in the Danish data and typically found in UK and US data. To reconcile the results with existing studies, I illustrate how ignoring precautionary motives increases the estimated importance of children. The results indicate that precautionary motives might play a larger role than children...

  10. Data Flow in Relation to Life-Cycle Costing of Construction Projects in the Czech Republic

    Biolek, Vojtěch; Hanák, Tomáš; Marović, Ivan

    2017-10-01

    Life-cycle costing is an important part of every construction project, as it makes it possible to take into consideration future costs relating to the operation and demolition phase of a built structure. In this way, investors can optimize the project design to minimize the total project costs. Even though there have already been some attempts to implement BIM software in the Czech Republic, the current state of affairs does not support automated data flow between the bill of costs and applications that support building facility management. The main aim of this study is to critically evaluate the current situation and outline a future framework that should allow for the use of the data contained in the bill of costs to manage building operating costs.

  11. An economic-mathematical model for optimization of the electrical equipment maintenance parameters of the Bobov Dol mine power supply system

    Shishov, S.

    1990-01-01

    The model proposed helps to ground the quantitative evaluation of the maintenance parameters of the electrical equipment of the coal mine. In the process of simulation an assumption is made that no additional capital investments are needed - only the existing situation of the electric supply system is considered and the effect of the measures taken to increase its reliability. The model takes into account the annual operating expenses, the downtime costs, the power not supplied to the user due to breakdowns, the average total outage duration; the breakdowns intensity, the average time for serviceability restoration. The model is based on the statistical data from the equipment operation for a period of 3 years, as well as on the economical standards acting in this mine. The outage expenses calculations of two units of the Bobov Dol mine are presented as an illustrative example of the model testing. The model is realized as a software product written on PL-1. It can also simulate the effect of the personnel number as well as the annual reserves of spare parts of various equipment's makes. 2 tabs, 6 refs

  12. DEVELOPMENT OF A MAINTENANCE SCHEDULING MODEL FOR ...

    ... of minor maintenance, for each machine within this time span. In order to minimize the total cost of repairs and production. A numerical application of this development model in a case study is presented. Key words: Maintenance, modeling, scheduling, optimization. [Global Jnl Engineering Res. Vol.1(2) 2002: 107-118] ...

  13. Investigation of change in specifications during a product's lifecycle

    Sudin, Mohd Nizam Bin; Ahmed, Saeema

    2009-01-01

    design attributes likely be changed; the initiation of change and how change in specifications are described. For this purpose, document analysis for a complex product has been carried out. In total, 271 reports of change request of an aero-engine that were associated to change in specifications were......Engineering changes (ECs) constitutes a normal part of a product’s lifecycle. This paper aims to understand why changes are made to a product’s specification during a product’s lifecycle including understanding: the distribution of changes; the drivers for changes; how changes are discovered; which...... the request was initiated. The study showed that experience plays a vital role in discovering the need to change a complex product...

  14. Lifecycle assessment of fuel ethanol from sugarcane in Brazil

    Ometto, A. R.; Hauschild, Michael Zwicky; Roma, W. N. L.

    2009-01-01

    This paper presents the lifecycle assessment (LCA) of fuel ethanol, as 100% of the vehicle fuel, from sugarcane in Brazil. The functional unit is 10,000 km run in an urban area by a car with a 1,600-cm(3) engine running on fuel hydrated ethanol, and the resulting reference flow is 1,000 kg......, and study cases at sugarcane farms and fuel ethanol industries in the northeast of SA o pound Paulo State, Brazil. The methodological structure for this LCA study is in agreement with the International Standardization Organization, and the method used is the Environmental Design of Industrial Products...... fuel. The recommendations for the ethanol lifecycle are: harvesting the sugarcane without burning; more environmentally benign agricultural practices; renewable fuel rather than diesel; not washing sugarcane and implementing water recycling systems during the industrial processing; and improving...

  15. Rearing and estimation of life-cycle parameters of the tubicifid worm Branchiura sowerbyi: application to ecotoxicity testing.

    Ducrot, Virginie; Péry, Alexandre R R; Quéau, Hervé; Mons, Raphaël; Lafont, Michel; Garric, Jeanne

    2007-10-01

    This paper provides original collection, acclimatizing, rearing and toxicity test methods for the freshwater worm Branchiura sowerbyi, an alternative species to Tubifex tubifex for ecotoxicity evaluation of sediments. Influence of the substrate, type of food, and feeding level on individual performances was assessed in short-term tests, in order to set up optimal culture and test conditions. Low-size particles and high organic matter content favoured the growth and reproduction of B. sowerbyi. The relative contribution of sediments and fish food to the individual food intake was assessed using a foraging efficiency model based upon the dynamic energy budget theory. Individual performances were optimal when the substrate plus fish food provided the energy equivalent to 5 mg Tetramin per worm per day, which is the ad libitum food level for adults at 21 degrees C. The life-cycle of the worm was fully characterized using a life-cycle test conducted under the previously defined optimal conditions. Hatching rates were low (32%), whereas newborn and juveniles exhibited high survival (>80%) and growth (2.4 mg/day in juveniles) rates. Age at puberty was low (60 days) when compared to the maximal life span (1100 days) as predicted using a Weibull model. Adults reproduced every other month with a constant fecundity (0.16 cocoon/worm/day). The mean values of the life-cycle parameters and their variability and reproducibility among laboratory studies were discussed in order to identify relevant endpoints to be used in ecotoxicity tests. Survival, juvenile growth, and fecundity may constitute suitable test endpoints, whereas hatching rate and adult growth should not be used as endpoints in B. sowerbyi.

  16. A Life-Cycle Analysis of Social Security with Housing

    Chen, Kaiji

    2009-01-01

    This paper incorporates two features of housing in a life-cycle analysis of social security: housing as a durable good and housing market frictions. We find that with housing as a durable good unfunded social security substantially crowds out housing consumption throughout the life cycle. By contrast, aggregate non-durable consumption is higher when social security is present, although it is postponed until late in life. Moreover, in the presence of housing market frictions, social security l...

  17. PROCESS OF INNOVATION IN PRODUCT LIFECYCLE MANAGEMENT BUSINESS STRATEGY

    VALENTINA GECEVSKA; FRANC CUS; RADMIL POLENAKOVIC; PAOLO CHABERT

    2011-01-01

    This article proposes a scenario of Product Lifecycle Management (PLM), as a innovative business strategy based on the analysis of business drivers, industry requirements, limit of current solution, and recent state-of-the-art review in the domain related to PLM. Potential industrial impact of the developed PLM technology solutions is analyzed. It is hoped that the proposed PLM technology solutions will form the frontier basis for further research, development, and application of PLM systems ...

  18. Understanding Cloud Requirements - A Supply Chain Lifecycle Approach

    Lindner, Mark; McDonald, Fiona; Conway, Gerry; Curry, Edward

    2011-01-01

    Cloud Computing is offering competitive advantages to companies through flexible and, scalable access to computing resources. More and more companies are moving to cloud environments; therefore understanding the requirements for this process is both important and beneficial. The requirements for migrating from a traditional computing environment to a cloud hosting environment are discussed in this paper, considering this migration from a supply chain lifecycle perspective...

  19. Anti-schistosomal intervention targets identified by lifecycle transcriptomic analyses.

    Jennifer M Fitzpatrick

    2009-11-01

    Full Text Available Novel methods to identify anthelmintic drug and vaccine targets are urgently needed, especially for those parasite species currently being controlled by singular, often limited strategies. A clearer understanding of the transcriptional components underpinning helminth development will enable identification of exploitable molecules essential for successful parasite/host interactions. Towards this end, we present a combinatorial, bioinformatics-led approach, employing both statistical and network analyses of transcriptomic data, for identifying new immunoprophylactic and therapeutic lead targets to combat schistosomiasis.Utilisation of a Schistosoma mansoni oligonucleotide DNA microarray consisting of 37,632 elements enabled gene expression profiling from 15 distinct parasite lifecycle stages, spanning three unique ecological niches. Statistical approaches of data analysis revealed differential expression of 973 gene products that minimally describe the three major characteristics of schistosome development: asexual processes within intermediate snail hosts, sexual maturation within definitive vertebrate hosts and sexual dimorphism amongst adult male and female worms. Furthermore, we identified a group of 338 constitutively expressed schistosome gene products (including 41 transcripts sharing no sequence similarity outside the Platyhelminthes, which are likely to be essential for schistosome lifecycle progression. While highly informative, statistics-led bioinformatics mining of the transcriptional dataset has limitations, including the inability to identify higher order relationships between differentially expressed transcripts and lifecycle stages. Network analysis, coupled to Gene Ontology enrichment investigations, facilitated a re-examination of the dataset and identified 387 clusters (containing 12,132 gene products displaying novel examples of developmentally regulated classes (including 294 schistosomula and/or adult transcripts with no

  20. Life-cycle analysis of shale gas and natural gas.

    Clark, C.E.; Han, J.; Burnham, A.; Dunn, J.B.; Wang, M. (Energy Systems); ( EVS)

    2012-01-27

    The technologies and practices that have enabled the recent boom in shale gas production have also brought attention to the environmental impacts of its use. Using the current state of knowledge of the recovery, processing, and distribution of shale gas and conventional natural gas, we have estimated up-to-date, life-cycle greenhouse gas emissions. In addition, we have developed distribution functions for key parameters in each pathway to examine uncertainty and identify data gaps - such as methane emissions from shale gas well completions and conventional natural gas liquid unloadings - that need to be addressed further. Our base case results show that shale gas life-cycle emissions are 6% lower than those of conventional natural gas. However, the range in values for shale and conventional gas overlap, so there is a statistical uncertainty regarding whether shale gas emissions are indeed lower than conventional gas emissions. This life-cycle analysis provides insight into the critical stages in the natural gas industry where emissions occur and where opportunities exist to reduce the greenhouse gas footprint of natural gas.

  1. Life-Cycle Evaluation of Domestic Energy Systems

    Bando, Shigeru; Hihara, Eiji

    Among the growing number of environmental issues, the global warming due to the increasing emission of greenhouse gases, such as carbon dioxide CO2, is the most serious one. In order to reduce CO2 emissions in energy use, it is necessary to reduce primary energy consumption, and to replace energy sources with alternatives that emit less CO2.One option of such ideas is to replace fossil gas for water heating with electricity generated by nuclear power, hydraulic power, and other methods with low CO2 emission. It is also important to use energy efficiently and to reduce waste heat. Co-generation system is one of the applications to be able to use waste heat from a generator as much as possible. The CO2 heat pump water heaters, the polymer electrolyte fuel cells, and the micro gas turbines have high potential for domestic energy systems. In the present study, the life-cycle cost, the life-cycle consumption of primary energy and the life-cycle emission of CO2 of these domestic energy systems are compare. The result shows that the CO2 heat pump water heaters have an ability to reduce CO2 emission by 10%, and the co-generation systems also have another ability to reduce primary energy consumption by 20%.

  2. Improving Life-Cycle Cost Management of Spacecraft Missions

    Clardy, Dennon

    2010-01-01

    This presentation will explore the results of a recent NASA Life-Cycle Cost study and how project managers can use the findings and recommendations to improve planning and coordination early in the formulation cycle and avoid common pitfalls resulting in cost overruns. The typical NASA space science mission will exceed both the initial estimated and the confirmed life-cycle costs by the end of the mission. In a fixed-budget environment, these overruns translate to delays in starting or launching future missions, or in the worst case can lead to cancelled missions. Some of these overruns are due to issues outside the control of the project; others are due to the unpredictable problems (unknown unknowns) that can affect any development project. However, a recent study of life-cycle cost growth by the Discovery and New Frontiers Program Office identified a number of areas that are within the scope of project management to address. The study also found that the majority of the underlying causes for cost overruns are embedded in the project approach during the formulation and early design phases, but the actual impacts typically are not experienced until late in the project life cycle. Thus, project management focus in key areas such as integrated schedule development, management structure and contractor communications processes, heritage and technology assumptions, and operations planning, can be used to validate initial cost assumptions and set in place management processes to avoid the common pitfalls resulting in cost overruns.

  3. Life-Cycle Assessment of Pyrolysis Bio-Oil Production*

    Steele, Philip; Puettmann, Maureen E.; Penmetsa, Venkata Kanthi; Cooper, Jerome E.

    2012-07-01

    As part ofthe Consortium for Research on Renewable Industrial Materials' Phase I life-cycle assessments ofbiofuels, lifecycle inventory burdens from the production of bio-oil were developed and compared with measures for residual fuel oil. Bio-oil feedstock was produced using whole southern pine (Pinus taeda) trees, chipped, and converted into bio-oil by fast pyrolysis. Input parameters and mass and energy balances were derived with Aspen. Mass and energy balances were input to SimaPro to determine the environmental performance of bio-oil compared with residual fuel oil as a heating fuel. Equivalent functional units of 1 MJ were used for demonstrating environmental preference in impact categories, such as fossil fuel use and global warming potential. Results showed near carbon neutrality of the bio-oil. Substituting bio-oil for residual fuel oil, based on the relative carbon emissions of the two fuels, estimated a reduction in CO2 emissions by 0.075 kg CO2 per MJ of fuel combustion or a 70 percent reduction in emission over residual fuel oil. The bio-oil production life-cycle stage consumed 92 percent of the total cradle-to-grave energy requirements, while feedstock collection, preparation, and transportation consumed 4 percent each. This model provides a framework to better understand the major factors affecting greenhouse gas emissions related to bio-oil production and conversion to boiler fuel during fast pyrolysis.

  4. Exploring the Client–AEC Interface in Building Lifecycle Integration

    John M. Kamara

    2013-07-01

    Full Text Available The creation and management of buildings over their lifecycle involves the cooperation of many organizations, which broadly fall into a client domain and AEC (architecture, engineering, construction domain. While this mix of expertise is essential, the ineffective management of the boundaries between these organizations can undermine building lifecycle performance. This paper explores client–AEC interactions at the project development and handover stages, with a view to discovering insights into client–AEC interface management for effective building lifecycle integration (BLI. The concept of boundary objects provided the theoretical framework to discuss findings from two case studies on the project development phase of a private finance initiative project, and the asset development process in a repeat client organization. The findings suggest that there are different emphases in boundary crossing activities at different stages, with boundary roles that relate to decision-making and authority to commit resources being more relevant at the project development stage, whereas the need to explain meanings appear to be more relevant at the handover stage. AEC professionals in client organizations play a crucial role in bridging knowledge boundaries about buildings, but this professional/functional strand to BLI needs to be effectively managed alongside the organizational boundaries, since the authority to resource BLI efforts resides within organizations.

  5. Knowledge engineering thinking of maintenance

    2007-01-01

    Maintenance optimization problem could not always settled mathematically and was obliged to use quasi-optimum solution with omitting non-formulated limiting condition or neglecting part of optimization object. In such a case knowledge engineering thinking was encouraged. Maintenance of complicated plant and artificial system should be considered from artificial object (equipment/facility hardware and system), technical information and knowledge base, and organizational and human aspect or society and institution. Comprehensive management system in organization and society was necessary not only for assuring integrity of equipment but also for attaining higher performance, reliability and economics of system. For better judgment it was important to share mechanism to make use of more information with organization or whole society. It was required to create database and data mining for knowledge base management system of maintenance. Maintenance was called 'last fortress' to assure quality such as reliability and safety of required function of equipment. Strategic approach to develop maintenance technology under cooperation was considered. Life extension R and D road map was launched in 2005. (T. Tanaka)

  6. North American nuclear maintenance best practices compared to Japanese utility maintenance practices

    Harazim, M.L.; Ferguson, B.J.

    2003-01-01

    The purpose of this paper is to compare the best practices in North America concerning Preventive Maintenance, Predictive Maintenance and Reliability Centered Maintenance (RCM) or Preventive Maintenance Optimization (PMO) with the time-directed maintenance philosophies utilized by Japanese utilities, and how the Japanese utilities are considering (and some have begun) adopting North American ways of doing business. Preventive Maintenance Living Programs are also discussed, along with the Institute of Nuclear Power Operations AP-913 process, Equipment Reliability Process. Also, a cost benefit analysis will be demonstrated showing how major cost savings can be achieved by shifting from a predominantly time-directed maintenance philosophy to a predominantly predictive strategy utilizing vibration analysis, lubricating oil analysis, thermography and other predictive technologies to better utilize resources, reduce spare part consumption and to minimize maintenance induced errors. As a result of the strides made while incorporating these new philosophies, we no longer advocate tearing apart perfectly good equipment. (author)

  7. Maintenance Business Plans.

    Adams, Matt

    2002-01-01

    Discusses maintenance business plans, statements which provide accountability for facilities maintenance organizations' considerable budgets. Discusses the plan's components: statement of plan objectives, macro and detailed description of the facility assets, maintenance function descriptions, description of key performance indicators, milestone…

  8. Maintenance Management Update.

    Sternloff, Robert E.

    1987-01-01

    Current trends in park maintenance are overviewed, including maintenance impact statements, avoidance of cost through efficient use and national resource conservation, horticultural accomplishments that influence maintenance management, and vandalism prevention. (CB)

  9. Forecasts of the Maintenance Activity

    Marius Romocea

    2017-11-01

    Full Text Available Enhancing the machines’ technical and technological performance through constructive improvements that allow for the automation of orders, contributes to the increasing of the production capacity of the system and for maintaining an optimal level of product costs. In order to achieve these goals, it is necessary to organize the maintenance work well, in order to quickly diagnose the malfunctions and to shorten the repair time. Given the scale of the phenomena, this paper seeks to answer two questions, namely: how will be the maintenance in future and also how to prepare this activity.

  10. Electric motor predictive and preventive maintenance guide

    Oliver, J.A.

    1992-07-01

    Electric motor performance is vital to the reliable and efficient operation of power plants. The failure of one or more critical motors could cause lost capacity and excessive repair and maintenance cost. However, existing maintenance recommendations proposed by vendors for electric motors have sometimes encouraged many overly conservative maintenance practices. These practices have lead to excessive maintenance activities and costs which have provided no extra margin of operability. EPRI has sponsored RP2814-35 to develop a guide which provides power plants with information and guidance for establishing an effective maintenance program which will aid in preventing unexpected motor failures and assist in planning motor maintenance efforts. The guide includes a technical description which summarizes technical data relative to the four basic types of motors and their components in general use in power plants. The significant causes of motor failures are investigated and described in detail and methods to optimize service life and minimize maintenance cost through appropriate preventive maintenance and conditioning program are presented. This guide provides a foundation for an effective electric motor maintenance program and simplifies the selection of predictive and preventive maintenance tasks. Its use will enable maintenance personnel in nuclear and fossil plants to plan motor repairs during scheduled outages and avoid costly unexpected failures

  11. Task oriented evaluation system for maintenance robots

    Asame, Hajime; Endo, Isao; Kotosaka, Shin-ya; Takata, Shozo; Hiraoka, Hiroyuki; Kohda, Takehisa; Matsumoto, Akihiro; Yamagishi, Kiichiro.

    1994-01-01

    The adaptability evaluation of maintenance robots to autonomous plants has been discussed. In this paper, a new concept of autonomous plant with maintenance robots are introduced, and a framework of autonomous maintenance system is proposed. Then, task-oriented evaluation of robot arms is discussed for evaluating their adaptability to maintenance tasks, and a new criterion called operability is proposed for adaptability evaluation. The task-oriented evaluation system is implemented and applied to structural design of robot arms. Using genetic algorithm, an optimal structure adaptable to a pump disassembly task is obtained. (author)

  12. A Framework for BIM-Enabled Life-Cycle Information Management of Construction Project

    Xun Xu

    2014-08-01

    Full Text Available BIM has been widely used in project management, but on the whole the applications have been scattered and the BIM models have not been deployed throughout the whole project life-cycle. Each participant builds their own BIM, so there is a major problem in how to integrate these dynamic and fragmented data together. In order to solve this problem, this paper focuses on BIM-based life-cycle information management and builds a framework for BIM-enabled life-cycle information management. To organize the life-cycle information well, the information components and information flow during the project life-cycle are defined. Then, the application of BIM in life-cycle information management is analysed. This framework will provide a unified platform for information management and ensure data integrity.

  13. Maintenance analysis method and operational feedback: a comprehensive maintenance management

    Mathieu Riou; Victor Planchon

    2006-01-01

    Full text of publication follows: Current periodic inspections program carried out on the COGEMA LOGISTICS casks is required by regulations and approved by the competent Authority. Thus, Safety and casks conformity to the according certificate of approval are guaranteed. Nonetheless, based on experience it appeared that some maintenance operations did not seem relevant or were redundant. Then, it was decided to rethink completely our maintenance program to reach the following objectives: - Set up the 'a minima' required inspection operations required to guarantee Safety and conformity to the certificate of approval, - Optimize criteria and periodicities of inspections taking into account: operational feedback, routine inspections carried out for each transport, regulations, environmental impact (ALARA, waste reduction,...), cost-effectiveness (reduction of cask's immobilization period,...). - Set up a maintenance program in Safety Analysis Reports that: stands alone (no need to check the specification or the certificate of approval to have the complete list of inspections mandatory to guarantee Safety), gives objectives instead of means of controls. This approach needs then to be re-evaluated by the competent Authority. Study's scope has been limited to the TN TM 12 cask family which is intensely used. COGEMA LOGISTICS has a high operational feedback on these casks. After Authority agreement, and in accordance with its requirements, study will then be extended to the other casks belonging to the COGEMA LOGISTICS cask fleet. Actually, the term 'maintenance' is linked to 'Base maintenance' and 'Main maintenance' and implicitly means that the cask is immobilized for a given period. To emphasize the modifications, the term 'maintenance' is no longer used and is substituted by 'periodic upkeep'. By changing the name, COGEMA LOGISTICS wants to emphasize that: some operations can for instance be realized while the cask is unloaded, periodicities are thought in terms of

  14. Multiscale design and life-cycle based sustainability assessment of polymer nanocomposite coatings

    Uttarwar, Rohan G.

    In recent years, nanocoatings with exceptionally improved and new performance properties have found numerous applications in the automotive, aerospace, ship-making, chemical, electronics, steel, construction, and many other industries. Especially the formulations providing multiple functionalities to cured paint films are believed to dominate the coatings market in the near future. It has shifted the focus of research towards building sustainable coating recipes which can deliver multiple functionalities through applied films. The challenge to this exciting area of research arrives from the insufficient knowledge about structure-property correlations of nanocoating materials and their design complexity. Experimental efforts have been successful in developing certain types of nanopaints exhibiting improved properties. However, multifunctional nanopaint design optimality is extremely difficult to address if not impossible solely through experiments. In addition to this, the environmental implications and societal risks associated with this growing field of nanotechnology raise several questions related to its sustainable development. This research focuses on the study of a multiscale sustainable nanocoating design which can have the application from novel function envisioning and idea refinement point of view, to knowledge discovery and design solution derivation, and further to performance testing in industrial applications. The nanocoating design is studied using computational simulations of nano- to macro- scale models and sustainability assessment study over the life-cycle. Computational simulations aim at integrating top-down, goals/means, inductive systems engineering and bottom-up, cause and effect, deductive systems engineering approaches for material development. The in-silico paint resin system is a water-dispersible acrylic polymer with hydrophilic nanoparticles incorporated into it. The nano-scale atomistic and micro-scale coarse-grained (CG) level

  15. Operation and maintenance requirements of system design bases

    Banerjee, A.K.; Hanley, N.E.

    1989-01-01

    All system designs make assumptions about system operation testing, inspection, and maintenance. Existing industry codes and standards explicitly address design requirements of new systems, while issues related to system and plant reliability, life, design margins, effects of service conditions, operation, maintenance, etc., usually are implicit. However, system/component design documents of existing power plants often address the code requirements without considering the operation, maintenance, inspection, and testing (OMIT) requirements. The nuclear industry is expending major efforts at most nuclear power plants to reassemble and/or reconstitute system design bases. Stone ampersand Webster Engineering Corporation (SWEC) recently addressed the OMIT requirements of system/component design as an integral part of a utility's preventive maintenance program. For each component, SWEC reviewed vendor recommendations, NPRDS data/industry experience, the existing maintenance program, component service conditions, and actual plant experience. A maintenance program that considers component service conditions and plant experience ensures a connection between maintenance and design basis. Root cause analysis of failure and engineering evaluation of service condition are part of the program. System/component OMIT requirements also are compared against system design, service condition, degradation mechanism, etc., through system/component life-cycle evaluation

  16. Life-cycle cost assessment of seismically base-isolated structures in nuclear power plants

    Wang, Hao; Weng, Dagen; Lu, Xilin; Lu, Liang

    2013-01-01

    Highlights: • The life-cycle cost of seismic base-isolated nuclear power plants is modeled. • The change law of life-cycle cost with seismic fortification intensity is studied. • The initial cost of laminated lead rubber bearings can be expressed as the function of volume. • The initial cost of a damper can be expressed as the function of its maximum displacement and tonnage. • The use of base-isolation can greatly reduce the expected damage cost, which leads to the reduction of the life-cycle cost. -- Abstract: Evaluation of seismically base-isolated structural life-cycle cost is the key problem in performance based seismic design. A method is being introduced to address the life-cycle cost of base-isolated reinforced concrete structures in nuclear power plants. Each composition of life-cycle cost is analyzed including the initial construction cost, the isolators cost and the excepted damage cost over life-cycle of the structure. The concept of seismic intensity is being used to estimate the expected damage cost, greatly simplifying the calculation. Moreover, French Cruas nuclear power plant is employed as an example to assess its life-cycle cost, compared to the cost of non-isolated plant at the same time. The results show that the proposed method is efficient and the expected damage cost is enormously reduced because of the application of isolators, which leads to the reduction of the life-cycle cost of nuclear power plants

  17. Maintenance evaluation using risk based criteria

    Torres Valle, A.

    1996-01-01

    The maintenance evaluation is currently performed by using economic and, in some case, technical equipment failure criteria, however this is done to a specific equipment level. In general, when statistics are used the analysis for maintenance optimization are made isolated and whit a post mortem character; The integration provided by mean of Probabilistic Safety assessment (PSA) together with the possibilities of its applications, allow for evaluation of maintenance on the basis of broader scope criteria in regard to those traditionally used. The evaluate maintenance using risk based criteria, is necessary to follow a dynamic and systematic approach, in studying the maintenance strategy, to allow for updating the initial probabilistic models, for including operational changes that often take place during operation of complex facilities. This paper proposes a dynamic evaluation system of maintenance task. The system is illustrated by means of a practical example

  18. Upgrade of maintenance technologies of Nuclear Power Plants

    Kamada, Kazuaki

    2005-01-01

    In order to enhance long-term safe and stable operation of Ikata Nuclear Power Plants (NPPs) in more efficient way, maintenance technology upgrade project was started aiming at establishment of simplified and efficient self-maintenance system with affiliated companies. Maintenance technique and supervisor qualification system was introduced after improvement and reinforcement of personnel education and training. Reflecting investigation of maintenance activities of US NPPs and productivity improvement in other industries, preventive maintenance optimization project had been performed such as introduction of key performance indicator (KPI), new system incorporating reliability-centered maintenance (RCM) and condition-based maintenance (CBM), and on-line monitoring and maintenance (OLM) based on risk assessment. Enterprise asset management (EAM) to establish information data base and total productive maintenance (TPM) action for every personnel to participate in self-maintenance was also introduced. (T. Tanaka)

  19. Development of Mathematical Model for Lifecycle Management Process of New Type of Multirip Saw Machine

    B. V. Phung

    2017-01-01

    Full Text Available The subject of research is a new type of the multirip saw machine with circular reciprocating saw blades. This machine has a number of advantages in comparison with other machines of similar purpose. The paper presents an overview of different types of saw equipment and describes basic characteristics of the machine under investigation.Using the concept of lifecycle management of the considered machine in a unified information space is necessary to improve quality and competitiveness in the current production environment. In this lifecycle all the members, namely designers, technologists, customers, etc., have a philosophy to tend to optimize the overall machine design as much as possible. However, it is not always possible to achieve. Conversely, at the boundary between the phases there are several mismatching situations, if not even conflicting inconsistencies. For example, improvement of mass characteristics can lead to poor stability and rigidity of the saw blade. Machine output improvement through increasing frequency of the machine motor rotation, on the other side, results in reducing stable ability of the saw blades and so on.In order to provide a coherent framework for the collaborative environment between the members of the life cycle, the article presents a technique to construct a mathematical model that allows combining all different members’ requirements in the unified information model. The article also gives analysis of kinematic and dynamic behavior and technological characteristics of the machine. Describes in detail all the controlled parameters, functional constraints, and quality criteria of the machine under consideration. Depending on the controlled parameters, the analytical relationships formulate functional constraints and quality criteria of the machine. The proposed algorithm allows fast and exact calculation of all the functional constraints and quality criteria of the machine for a given vector of the control

  20. FY 1997 survey report on information sharing product life-cycle systems. 2; 1997 nendo joho kyoyugata product life cycle system ni kansuru chosa hokokusho. 2

    NONE

    1998-03-01

    Highly value-added products considering a total life-cycle of products by integrating both production and consumption activities are much in demand, and each information corresponding to each product should be realized by concept integrating both information and product as common element. Survey was made on what a social system integrating production and consumption should be, a product information model, and technology integrating both information and product for raw material, industrial machine and household appliance as examples. An information model shared by the whole production and consumption activities was first prepared. Based on this model, data storage, update, retrieval and dispatch technologies were surveyed and developed for life-cycle systems. Degradation and life sensing technology was surveyed for maintenance, repair and disposal activities using proper unstable information of each product. A support system for use of shared information was developed to promote a new highly value-added function. Total evaluation was made on information sharing product life-cycle systems. 10 refs., 23 figs., 7 tabs.

  1. A Situational Maintenance Model

    Luxhoj, James T.; Thorsteinsson, Uffe; Riis, Jens Ove

    1997-01-01

    An overview of trend in maintenance management and presentation of a situational model and an analytical tools for identification of managerial efforts in maintenance.......An overview of trend in maintenance management and presentation of a situational model and an analytical tools for identification of managerial efforts in maintenance....

  2. Clinical Research Informatics: Supporting the Research Study Lifecycle.

    Johnson, S B

    2017-08-01

    Objectives: The primary goal of this review is to summarize significant developments in the field of Clinical Research Informatics (CRI) over the years 2015-2016. The secondary goal is to contribute to a deeper understanding of CRI as a field, through the development of a strategy for searching and classifying CRI publications. Methods: A search strategy was developed to query the PubMed database, using medical subject headings to both select and exclude articles, and filtering publications by date and other characteristics. A manual review classified publications using stages in the "research study lifecycle", with key stages that include study definition, participant enrollment, data management, data analysis, and results dissemination. Results: The search strategy generated 510 publications. The manual classification identified 125 publications as relevant to CRI, which were classified into seven different stages of the research lifecycle, and one additional class that pertained to multiple stages, referring to general infrastructure or standards. Important cross-cutting themes included new applications of electronic media (Internet, social media, mobile devices), standardization of data and procedures, and increased automation through the use of data mining and big data methods. Conclusions: The review revealed increased interest and support for CRI in large-scale projects across institutions, regionally, nationally, and internationally. A search strategy based on medical subject headings can find many relevant papers, but a large number of non-relevant papers need to be detected using text words which pertain to closely related fields such as computational statistics and clinical informatics. The research lifecycle was useful as a classification scheme by highlighting the relevance to the users of clinical research informatics solutions. Georg Thieme Verlag KG Stuttgart.

  3. Integrated manure utilization system life-cycle value assessment

    Row, J.; Neabel, D. [Pembina Inst. for Appropriate Development, Drayton Valley, AB (Canada)

    2005-10-15

    A life-cycle assessment of the Alberta Research Council (ARC) and Highmark Renewables' development of an integrated manure utilization system (IMUS) were presented. The assessment focused on an evaluation of factors of primary importance to government, investors and the livestock industry. IMUS technology uses manure as a resource to produce electricity, heat, bio-based fertilizer and reusable water. Results of the assessment indicated that IMUS plants have the potential to be financially viable if a power purchase of $90 MWh on average can be purchased from a 30,000 head livestock operation. A capital cost of under $11 million is necessary, and an established biofertilizer price of $50 per tonne should be established. An IMUS plant was estimated to reduce life-cycle greenhouse gas emissions by 70 to 80 per cent when compared to land spreading. Reductions are accomplished through displacing electricity from the provincial grid and reducing nitrous oxide (N{sub 2}O) emissions from spreading of manure The IMUS plants lessen environment impacts by reducing the extraction and consumption of non-renewable resources, and by displacing an estimated 11,700 GJ of coal and natural gas per 1000 head of cattle per year. In addition, various pathogens within manure are eliminated. The plants have the potential to eliminate the environmental hazards associated with the disposal of deadstock. The systems reduce manure odour, lessen truck traffic and are expected to contribute to rural economic diversification. Barriers to further implementation of IMUS were discussed, as well as emerging opportunities for IMUS developers. It was concluded that the initial assessments of the IMUS were positive. Further investigation is needed to determine actual life-cycle performance of the operations. 18 refs., 3 tabs., 3 figs.

  4. The NISTmAb Reference Material 8671 lifecycle management and quality plan.

    Schiel, John E; Turner, Abigail

    2018-03-01

    Comprehensive analysis of monoclonal antibody therapeutics involves an ever expanding cadre of technologies. Lifecycle-appropriate application of current and emerging techniques requires rigorous testing followed by discussion between industry and regulators in a pre-competitive space, an effort that may be facilitated by a widely available test metric. Biopharmaceutical quality materials, however, are often difficult to access and/or are protected by intellectual property rights. The NISTmAb, humanized IgG1κ Reference Material 8671 (RM 8671), has been established with the intent of filling that void. The NISTmAb embodies the quality and characteristics of a typical biopharmaceutical product, is widely available to the biopharmaceutical community, and is an open innovation tool for development and dissemination of results. The NISTmAb lifecyle management plan described herein provides a hierarchical strategy for maintenance of quality over time through rigorous method qualification detailed in additional submissions in the current publication series. The NISTmAb RM 8671 is a representative monoclonal antibody material and provides a means to continually evaluate current best practices, promote innovative approaches, and inform regulatory paradigms as technology advances. Graphical abstract The NISTmAb Reference Material (RM) 8671 is intended to be an industry standard monoclonal antibody for pre-competitive harmonization of best practices and designing next generation characterization technologies for identity, quality, and stability testing.

  5. Improving life-cycle cost management in the US. Army: analysis of the U.S. Army and Commercial Businesses life-cycle cost management.

    White, Bradley A.

    2001-01-01

    The roles and responsibilities of the Army acquisition and logistics communities, as they pertain to the life-cycle management, are undergoing fundamental change. The early identification and total control of life-cycle cost, in particular operations and sustainment costs which comprises as much as 70-80% of a systems total life-cycle cost, is a high priority for the Army. The basis of this change is adoption of commercial best practices to support the Army's goal to organize. tram. equip, an...

  6. Refined life-cycle assessment of polymer solar cells

    Lenzmann, F.; Kroon, J.; Andriessen, R.

    2011-01-01

    A refined life-cycle assessment of polymer solar cells is presented with a focus on critical components, i.e. the transparent conductive ITO layer and the encapsulation components. This present analysis gives a comprehensive sketch of the full environmental potential of polymer-OPV in comparison...... with other PV technologies. It is shown that on a m2 basis the environmental characteristics of polymer-OPV are highly beneficial, while on a watt-peak and on a kWh basis, these benefits are - at the current level of the development - still (over-)compensated by low module efficiency and limited lifetime...

  7. Engineering Documentation Control Handbook Configuration Management and Product Lifecycle Management

    Watts, Frank B

    2011-01-01

    In this new edition of his widely-used Handbook, Frank Watts, widely recognized for his significant contributions to engineering change control processes, provides a thoroughly practical guide to the implementation and improvement of Engineering Documentation Control (EDC), Product Lifecycle Management and Product Configuration Management (CM). Successful and error-free implementation of EDC/CM is critical to world-class manufacturing. Huge amounts of time are wasted in most product manufacturing environments over EDC/CM issues such as interchangeability, document release and change control -

  8. Site-dependent life-cycle impact assessment of acidification

    Potting, Josepha Maria Barbara; Schöpp, W.; Blok, Kornelis

    1998-01-01

    The lack of spatial differentiation in current life-cycle impact assessment (LCIA) affects the relevance of the assessed impact. This article first describes a framework for constructing factors relating the region of emission to the acidifying impact on its deposition areas. Next, these factors...... are established for 44 European regions with the help of the RAINS model, an integrated assessment model that combines information on regional emission levels with information on long-range atmospheric transport to estimate patterns of deposition and concentration for comparison with critical loads and thresholds...

  9. Analysis within the systems development life-cycle

    Rock-Evans, Rosemary

    1987-01-01

    Analysis within the Systems Development Life-Cycle, Book 3: Activity Analysis - The Deliverables provides a comprehensive coverage of the deliverables of activity analysis. The book also details purpose of each deliverable in the context of the next tasks in the systems development cycle (SDC). The text first covers the concept of deliverables and the benefits of making deliverables visible. In the second chapter, the book introduces the main concepts and diagrammatic techniques of activity analysis. The third chapter deals with the important classes or categories of concept, while the fourth

  10. Societal lifecycle costs of cars with alternative fuels/engines

    Ogden, Joan M.; Williams, Robert H.; Larson, Eric D.

    2004-01-01

    Effectively addressing concerns about air pollution (especially health impacts of small-particle air pollution), climate change, and oil supply insecurity will probably require radical changes in automotive engine/fuel technologies in directions that offer both the potential for achieving near-zero emissions of air pollutants and greenhouse gases and a diversification of the transport fuel system away from its present exclusive dependence on petroleum. The basis for comparing alternative automotive engine/fuel options in evolving toward these goals in the present analysis is the 'societal lifecycle cost' of transportation, including the vehicle first cost (assuming large-scale mass production), fuel costs (assuming a fully developed fuel infrastructure), externality costs for oil supply security, and damage costs for emissions of air pollutants and greenhouse gases calculated over the full fuel cycle. Several engine/fuel options are considered--including current gasoline internal combustion engines and a variety of advanced lightweight vehicles: internal combustion engine vehicles fueled with gasoline or hydrogen; internal combustion engine/hybrid electric vehicles fueled with gasoline, compressed natural gas, Diesel, Fischer-Tropsch liquids or hydrogen; and fuel cell vehicles fueled with gasoline, methanol or hydrogen (from natural gas, coal or wind power). To account for large uncertainties inherent in the analysis (for example in environmental damage costs, in oil supply security costs and in projected mass-produced costs of future vehicles), lifecycle costs are estimated for a range of possible future conditions. Under base-case conditions, several advanced options have roughly comparable lifecycle costs that are lower than for today's conventional gasoline internal combustion engine cars, when environmental and oil supply insecurity externalities are counted--including advanced gasoline internal combustion engine cars, internal combustion engine

  11. Design for life-cycle profit with simultaneous consideration of initial manufacturing and end-of-life remanufacturing

    Kwak, Minjung; Kim, Harrison

    2015-01-01

    Remanufacturing is emerging as a promising solution for achieving green, profitable businesses. This article considers a manufacturer that produces new products and also remanufactured versions of the new products that become available at the end of their life cycle. For such a manufacturer, design decisions at the initial design stage determine both the current profit from manufacturing and future profit from remanufacturing. To maximize the total profit, design decisions must carefully consider both ends of product life cycle, i.e. manufacturing and end-of-life stages. This article proposes a decision-support model for the life-cycle design using mixed-integer nonlinear programming. With an aim to maximize the total life-cycle profit, the proposed model searches for an (at least locally) optimal product design (i.e. design specifications and the selling price) for the new and remanufactured products. It optimizes both the initial design and design upgrades at the end-of-life stage and also provides corresponding production strategies, including production quantities and take-back rate. The model is extended to a multi-objective model that maximizes both economic profit and environmental-impact saving. To illustrate, the developed model is demonstrated with an example of a desktop computer.

  12. Utility based maintenance analysis using a Random Sign censoring model

    Andres Christen, J.; Ruggeri, Fabrizio; Villa, Enrique

    2011-01-01

    Industrial systems subject to failures are usually inspected when there are evident signs of an imminent failure. Maintenance is therefore performed at a random time, somehow dependent on the failure mechanism. A competing risk model, namely a Random Sign model, is considered to relate failure and maintenance times. We propose a novel Bayesian analysis of the model and apply it to actual data from a water pump in an oil refinery. The design of an optimal maintenance policy is then discussed under a formal decision theoretic approach, analyzing the goodness of the current maintenance policy and making decisions about the optimal maintenance time.

  13. Reliability-based maintenance evaluations and standard preventive maintenance programs

    Varno, M.; McKinley, M.

    1993-01-01

    Due to recent issuance of 10CFR50.65, the U.S. Nuclear Regulatory Commission maintenance rule (Rule), and the open-quotes Industry Guideline for Monitoring the Effectiveness of Maintenance at Nuclear Power Plantsclose quotes prepared by the Nuclear Management and Resources Council, many utilities are undertaking review or evaluation of current preventive maintenance (PM) programs. Although PM optimization and documentation are not specifically required by the Rule, an appropriate and effective PM program (PMP) will be the cornerstone of the successful and cost-effective implementation of the Rule. Currently, a project is being conducted at the Vermont Yankee Nuclear Power Station (VYNPS) in conjunction with Quadrex Energy Services to evaluate, optimize, and document the PMP. The project began in March 1993 and is scheduled for completion in mid-1995. The initial scope for the project is the evaluation of those structures, systems, and components that are within the scope of the Rule. Because of the number of systems to be evaluated (∼50), the desired completion schedule, and cost considerations, a streamlined approach to PM optimization and documentation is being utilized

  14. Preventive maintenance and reliability-centered maintenance

    Anderson, J.G.

    1989-01-01

    In the recent past, the primary function of the preventive maintenance program at a nuclear power plant was to maintain the operability and reliability of the plant. Reducing overall maintenance costs by performing effective preventive maintenance, instead of more costly and disruptive corrective maintenance, instead of more costly and disruptive corrective maintenance, was a secondary consideration. In today's operating environment, the preventive maintenance program must meet the test of cost-effectiveness as well as many new standards for performance that are being required by rate regulators. The preventive maintenance program must be able to withstand the challenge of independent audit to a new standard of technical adequacy and compliance with recommendations from component vendors. In this new environment, the standard that is being applied at the San Onofre nuclear generating station (SONGS) is that the preventive maintenance program must meet the test of cost-effectiveness, improve equipment performance, support increased plant availability, and (a) literally implement the recommendations of the vendor, (b) provide other compensation for the vendor recommendation, or (c) provide technical justification for the deviation. The subject of this paper is the way that reliability-centered maintenance (RCM) is helping SONGS meet these challenges

  15. Optimal Smooth Consumption and Annuity Design

    Bruhn, Kenneth; Steffensen, Mogens

    2013-01-01

    We propose an optimization criterion that yields extraordinary consumption smoothing compared to the well known results of the life-cycle model. Under this criterion we solve the related consumption and investment optimization problem faced by individuals with preferences for intertemporal stabil...... stability in consumption. We find that the consumption and investment patterns demanded under the optimization criterion is in general offered as annuity benefits from products in the class of ‘Formula Based Smoothed Investment-Linked Annuities’....

  16. System Evaluations and Life-Cycle Cost Analyses for High-Temperature Electrolysis Hydrogen Production Facilities

    Edwin A. Harvego; James E. O' Brien; Michael G. McKellar

    2012-05-01

    This report presents results of system evaluations and lifecycle cost analyses performed for several different commercial-scale high-temperature electrolysis (HTE) hydrogen production concepts. The concepts presented in this report rely on grid electricity and non-nuclear high-temperature process heat sources for the required energy inputs. The HYSYS process analysis software was used to evaluate both central plant designs for large-scale hydrogen production (50,000 kg/day or larger) and forecourt plant designs for distributed production and delivery at about 1,500 kg/day. The HYSYS software inherently ensures mass and energy balances across all components and it includes thermodynamic data for all chemical species. The optimized designs described in this report are based on analyses of process flow diagrams that included realistic representations of fluid conditions and component efficiencies and operating parameters for each of the HTE hydrogen production configurations analyzed. As with previous HTE system analyses performed at the INL, a custom electrolyzer model was incorporated into the overall process flow sheet. This electrolyzer model allows for the determination of the average Nernst potential, cell operating voltage, gas outlet temperatures, and electrolyzer efficiency for any specified inlet steam, hydrogen, and sweep-gas flow rates, current density, cell active area, and external heat loss or gain. The lifecycle cost analyses were performed using the H2A analysis methodology developed by the Department of Energy (DOE) Hydrogen Program. This methodology utilizes spreadsheet analysis tools that require detailed plant performance information (obtained from HYSYS), along with financial and cost information to calculate lifecycle costs. There are standard default sets of assumptions that the methodology uses to ensure consistency when comparing the cost of different production or plant design options. However, these assumptions may also be varied within the

  17. A predictive maintenance approach for improved nuclear plant availability

    Verma, R.M.P.; Pandya, M.B.; Kini, M.P.

    1979-01-01

    Predictive maintenance programme as against preventive maintenance programme aims at diagnosing, inspecting, monitoring, and objective condition-checking of equipment. It helps in forecasting failures, and scheduling the optimal frequencies for overhauls, replacements, lubrication etc. It also helps in establishing work load, manpower, resource planning and inventory control. Various stages of predictive maintenance programme for a nuclear power plant are outlined. A partial list of instruments for predictive maintenance is given. (M.G.B.)

  18. ROLE OF UML SEQUENCE DIAGRAM CONSTRUCTS IN OBJECT LIFECYCLE CONCEPT

    Miroslav Grgec

    2007-06-01

    Full Text Available When modeling systems and using UML concepts, a real system can be viewed in several ways. The RUP (Rational Unified Process defines the "4 + 1 view": 1. Logical view (class diagram (CD, object diagram (OD, sequence diagram (SD, collaboration diagram (COD, state chart diagram (SCD, activity diagram (AD, 2.Process view (use case diagram, CD, OD, SD, COD, SCD, AD, 3. Development view (package diagram, component diagram, 4. Physical view (deployment diagram, and 5. Use case view (use case diagram, OD, SD, COD, SCD, AD which combines the four mentioned above. With sequence diagram constructs we are describing object behavior in scope of one use case and their interaction. Each object in system goes through a so called lifecycle (create, supplement object with data, use object, decommission object. The concept of the object lifecycle is used to understand and formalize the behavior of objects from creation to deletion. With help of sequence diagram concepts our paper will describe the way of interaction modeling between objects through lifeline of each of them, and their importance in software development.

  19. Market Timing, lifecycle stage and Seasoned Equity offerings

    Vilma Sousa Ismael da Costa

    2014-08-01

    Full Text Available The tradeoff theory suggests that companies must issue shares to investments, when its leverage index is greater than your target rate, while the pecking order theory predicts that when capital offerings occur, the capital will be used to finance investments as the last source of funding, after their debt capacity have been exhausted. In contrast, the market timing theory predicts arguments that companies will adopt opportunistic behavior by issuing shares to take advantage of the high prices of the shares. Although the market timing theory has a significant influence on the decision to make a SEO, Brazilian literature contains little evidence about their economic importance and their effects. Thus, the present research aims to fill this gap in the Brazilian scenario. Specifically, we sought to assess the explanatory power of the relationship of market timing and the lifecycle theory in the issuance of SEO, which predicts that young companies with high market-to-book (MB and low operating cash flow sell shares to finance the investment, while mature companies, with low MB, pay dividends and fund investment internally. The sample was composed by non-financial companies with shares traded on BM&FBovespa. As main results, we can conclude that there is relationship between SEO and MB and size. On the other hand, were not observed evidence confirming the relationship between lifecycle stage and stock return, both in the previous year, and the year following the completion of the offer.

  20. QUALITY OF VOCATIONAL TRAINING THROUGH PRODUCT LIFECYCLE MANAGEMENT INSTRUMENTS

    Carmen\tCHAŞOVSCHI

    2015-12-01

    Full Text Available It appears that, during the process of continuous training, there is a growing need from VET providers of a reliable and easy to use tool ensuring the quality of the services provided. Product life cycle active management, including the use of suitable PLM software, is or may be a tool for monitoring and controlling product portfolio of an educational institution. It can be recommended not only for reasons of quality assurance, but also to facilitate the development of products for greater transparency in strategic business areas, and not least, to maintain competitiveness of VET providers. The Q-PLM project analysed the core of the product life cycle management in other sectors, identified the relevant variables that have an impact on the life cycle of VET provision and, on this basis, developed the beta version of a IT tool (software for product life cycle management addressed to VET providers, and a user manual for product life cycle management. The Q-PLM software makes possible the identification of the training products lifecycle, the life cycle stages, the key success factors and indicators for the training products lifecycle, separately for each training program and for each college.

  1. Advanced maintenance research programs

    Marston, T.U.; Gelhaus, F.; Burke, R.

    1985-01-01

    The purpose of this paper is to provide the reader with an idea of the advanced maintenance research program at the Electric Power Research Institute (EPRI). A brief description of the maintenance-related activities is provided as a foundation for the advanced maintenance research projects. The projects can be divided into maintenance planning, preventive maintenance program development and implementation, predictive (or conditional) maintenance, and innovative maintenance techniques. The projects include hardware and software development, human factors considerations, and technology promotion and implementation. The advanced concepts include: the incorporation of artificial intelligence into outage planning; turbine and pump maintenance; rotating equipment monitoring and diagnostics with the aid of expert systems; and the development of mobile robots for nuclear power plant maintenance

  2. Model based decision support for planning of road maintenance

    van Harten, Aart; Worm, J.M.; Worm, J.M.

    1996-01-01

    In this article we describe a Decision Support Model, based on Operational Research methods, for the multi-period planning of maintenance of bituminous pavements. This model is a tool for the road manager to assist in generating an optimal maintenance plan for a road. Optimal means: minimising the

  3. A Review of the Application of Lifecycle Analysis to Renewable Energy Systems

    Lund, Chris; Biswas, Wahidul

    2008-01-01

    The lifecycle concept is a "cradle to grave" approach to thinking about products, processes, and services, recognizing that all stages have environmental and economic impacts. Any rigorous and meaningful comparison of energy supply options must be done using a lifecycle analysis approach. It has been applied to an increasing number of conventional…

  4. Lifecycle greenhouse gas emissions of coal, conventional and unconventional natural gas for electricity generation

    An analysis of the lifecycle greenhouse gas (GHG) emissions associated with natural gas use recently published by Howarth et al. (2011) stated that use of natural gas produced from shale formations via hydraulic fracturing would generate greater lifecycle GHG emissions than petro...

  5. Life-cycle assessments in the South African water sector: A review ...

    Therefore, in South Africa it is important to promote the use of LCAs for the water sector in order to improve efficiency of processes and systems, but also to promote life-cycle based water footprinting and to include differentiated water consumption data into life-cycle inventories to make more efficient use of water as a ...

  6. Investigation into life-cycle costing as a comparative analysis approach of energy systems

    Mokheseng, B

    2010-08-31

    Full Text Available selection based on a simple payback period. Due to life-cycle stages, often the real costs of the project or equipment, either to the decision maker or the cost bearer, are not reflected by the upfront capital costs. In this paper, the life-cycle costing...

  7. Life-cycle assessment of textiles manufacture of polyester shirt (VB)

    Othman, Samer; Peter, Oduro Justice; Hassan, Osama

    1998-01-01

    According to the EDIP (Environmental Design of Industrial Products), It is made possible to perform resource and environmental profile analysis of the 100% polyester shirt. In order to understand the true life-cycle consequences, life-cycle analysis of a typical 100% polyester shirt was carried out...

  8. 77 FR 38766 - Proposed Information Collection; Comment Request; International Client Life-Cycle Multi-Purpose...

    2012-06-29

    ... Request; International Client Life-Cycle Multi-Purpose Forms AGENCY: International Trade Administration...-0151, 0625-0215, 0625-0220, 0625-0228, and 0625- 0238. These collections include all client intake... trade events to U.S. organizations. The International Client Life-cycle Multi-Purpose Forms, previously...

  9. A Life-Cycle Model of Outmigration and Economic Assimilation of Immigrants in Germany

    Bellemare, C.

    2004-01-01

    This paper estimates a structural dynamic life-cycle model of outmigration where, in each period, immigrants choose whether to work in the host country, not to work but remain in the host country, or outmigrate.The model incorporates several features of existing life-cycle theories of outmigration

  10. CRITICAL FACTORS THAT LEAD TO GREEN BUILDING OPERATIONS AND MAINTENANCE PROBLEMS IN MALAYSIA

    Izran Sarrazin MOHAMMAD; Nurul Nadiah ZAINOL; Shardy ABDULLAH; Neo Bee WOON; Nur Aqlima RAMLI

    2014-01-01

    The development of green buildings has become a trend in recent years in the effort to enhance the well-being of the community, environmental health, and life-cycle cost. However, many have argued that the complexities rendered by green buildings during the operational and maintenance phase often overshadow the benefits that can be gained through the development of green buildings. Several factors that lead to complexities in managing and maintaining green buildings have been highlighted by s...

  11. Techno-economic and life-cycle assessment of an attached growth algal biorefinery.

    Barlow, Jay; Sims, Ronald C; Quinn, Jason C

    2016-11-01

    This study examined the sustainability of generating renewable diesel via hydrothermal liquefaction (HTL) of biomass from a rotating algal biofilm reactor. Pilot-scale growth studies and laboratory-scale HTL experiments were used to validate an engineering system model. The engineering system model served as the foundation to evaluate the economic feasibility and environmental impact of the system at full scale. Techno-economic results indicate that biomass feedstock costs dominated the minimum fuel selling price (MFSP), with a base case of $104.31per gallon. Life-cycle assessment results show a base-case global warming potential (GWP) of 80gCO2-eMJ(-1) and net energy ratio (NER) of 1.65 based on a well-to-product system boundary. Optimization of the system reduces MFSP, GWP and NER to $11.90Gal(-1), -44gCO2-eMJ(-1), and 0.33, respectively. The systems-level impacts of integrating algae cultivation with wastewater treatment were found to significantly reduce environmental impact. Sensitivity analysis showed that algal productivity most significantly affected fuel selling price, emphasizing the importance of optimizing biomass productivity. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Pricing and Warranty Level Decisions for New and Remanufactured Short Life-Cycle Products

    Gan Shu San

    2017-06-01

    Full Text Available Remanufacturing has become more prominent as a recovery process to mitigate the massive disposal of short life-cycle product at its end-of-use. However, remanufactured product is often perceived to be inferior to new product, and it has lower value in consumer’s willingness to pay. To increase the perceived quality of the remanufactured product, manufacturer offers a warranty, since one of the three roles possessed in warranty is being a signal to product reliability. This paper studies the pricing decisions and warranty level decision for new and remanufactured products in a closed-loop supply chain consists of a manufacturer and a retailer. The optimization modeling is performed under Stackelberg game with manufacturer as the leader. We found that higher expansion effectiveness coefficient would increase the supply chain profit. Also, there is an interval of demand’s speed of change, where the total profit would be at its highest. The optimum warranty level can be achieved regardless the initial warranty level set at the beginning of retailer’s optimization. Furthermore, the remanufactured product’s wholesale and retail prices are influenced by the expansion effectiveness coefficient.

  13. Planning and control of maintenance systems modelling and analysis

    Duffuaa, Salih O

    2015-01-01

    Analyzing maintenance as an integrated system with objectives, strategies and processes that need to be planned, designed, engineered, and controlled using statistical and optimization techniques, the theme of this book is the strategic holistic system approach for maintenance. This approach enables maintenance decision makers to view maintenance as a provider of a competitive edge not a necessary evil. Encompassing maintenance systems; maintenance strategic and capacity planning, planned and preventive maintenance, work measurements and standards, material (spares) control, maintenance operations and control, planning and scheduling, maintenance quality, training, and others, this book gives readers an understanding of the relevant methodology and how to apply it to real-world problems in industry. Each chapter includes a number exercises and is suitable as a textbook or a reference for a professionals and practitioners whilst being of interest to industrial engineering, mechanical engineering, electrical en...

  14. State-of-the-Art Solid Waste Management Life-Cycle Modeling Workshop

    Damgaard, Anders; Levis, James W.

    There are many alternatives for the management of solid waste including recycling, biological treatment, thermal treatment and landfill disposal. In many cases, solid waste management systems include the use of several of these processes. Solid waste life-cycle assessment models are often used...... to evaluate the environmental consequences of various waste management strategies. The foundation of every life-cycle model is the development and use of process models to estimate the emissions from solid waste unit processes. The objective of this workshop is to describe life-cycle modeling of the solid...... waste processes and systems. The workshop will begin with an introduction to solid waste life-cycle modeling and available models, which will be followed by sessions on life-cycle process modeling for individual processes (e.g., landfills, biological treatment, and thermal treatment). The first part...

  15. Operations and maintenance - Safety challenges

    Nielsen, Liv [Oljedirektoratet, Stavanger (Norway)

    1999-07-01

    With the unsteady oil prices and the possible consequences of the deregulation of the European energy markets one may expect further optimization of operating and maintenance costs. One may also expect extended use of various risk-based optimization techniques such as RCM (Reliability Centered Maintenance) and RBI (Risk Based Inspection). This presentation addresses the need for further research and development in this area. Maintenance work is necessary, but it can also create risk. The accident statistics show many examples of this. The Norwegian petroleum industry's ability to learn from previous incidents is questioned. Maintenance staff must be well trained and possess the necessary routines. Technical documentation must be updated. Uncertainties with respect to future oil and gas prices combined with the effect of the deregulation of the European energy markets will lead to even more focus on cost-effective operations and maintenance. The need for long-term research and development is stressed. Risk based techniques such as RCM and RBI are extensively used in the defence industry and the nuclear industry, but applying them to the petroleum industry requires improved risk models. Ageing effects such as corrosion, erosion, fatigue etc. can be expected, but the capability to predict, monitor and control them should be improved. At present, not even the most sophisticated risk analysis can model ageing effects. The importance of efficient use of information technology (IT) is stressed. Improving the product quality and safety often requires new technology and so research and development is important. Close cooperation with the industry is required.

  16. Impact of Life-Cycle Stage and Gender on the Ability to Balance Work and Family Responsibilities.

    Higgins, Christopher; And Others

    1994-01-01

    Examined impact of gender and life-cycle stage on three components of work-family conflict using sample of 3,616 respondents. For men, levels of work-family conflict were moderately lower in each successive life-cycle stage. For women, levels were similar in two early life-cycle stages but were significantly lower in later life-cycle stage.…

  17. Valves maintenance management in nuclear power plants

    Trost, J.

    2001-01-01

    The deregulation of Europe's power market will force nuclear power plant operators to introduce extensive cost-cutting measures in order to be able to compete within this new environment. The optimization of plant outages provides considerable potential for raising plant availability but can also lower operating costs by reducing expenditure on maintenance. Framatome ANP GmbH, in cooperation with plant operators is currently developing new and improved service concepts which can have a major effect on the way in which maintenance will be performed in the future. The concepts encompass optimization of the overall sequence from planning in advance to the individual measures including reduction of the scope of maintenance activities, identification of cost cutting potential and bundling of maintenance activities. (Author)

  18. UTILITY OF A FULL LIFE-CYCLE COPEPOD BIOASSAY APPROACH FOR ASSESSMENT OF SEDIMENT-ASSOCIATED CONTAMINANT MIXTURES. (R825279)

    AbstractWe compared a 21 day full life-cycle bioassay with an existing 14 day partial life-cycle bioassay for two species of meiobenthic copepods, Microarthridion littorale and Amphiascus tenuiremis. We hypothesized that full life-cycle tests would bette...

  19. On maintenance management of wind and nuclear power plants

    Nilsson, Julia

    2009-11-01

    Electrical production in Sweden today is mainly from nuclear and hydro power. However, there is large increase in renewable energy like wind power and the installed new capacity goals are large. Several electrical production sources are important for the sustainability of the energy system. Maintenance is an approach for keeping a system sustainable. The importance of structured maintenance for reliable electrical production systems triggers the development of qualitative and quantitative maintenance management methods. Examples of these methods are Reliability-Centered Maintenance (RCM) which is a structured qualitative approach that focuses on reliability when planning maintenance, and Reliability Centered Asset Management (RCAM) which is a development of RCM into a quantitative approach with the aim to relate preventive maintenance to total maintenance cost and system reliability. This thesis presents models, as applications of RCAM, based on the methods of Life Cycle Cost (LCC) and mathematical optimization, applied to wind and nuclear power plants. Both deterministic and stochastic approaches have been used and the proposed models are based on the Total Cost model, which summarizes costs for maintenance and production loss, and the Aircraft model, which is an opportunistic maintenance optimization model. Opportunistic maintenance is preventive maintenance performed at opportunities. The wind power applications in this study show on different ways to cover costs of condition monitoring systems (CMS) and further on economic benefits of these when uncertainties of times to failure are included in the model. The nuclear power applications show on that the optimization model is dependent on the discount rate and that a high discount rate gives more motivation for opportunistic replacements. When put into a stochastic framework and compared to other maintenance strategies it is shown that an extended opportunistic maintenance optimization model has a good overall

  20. Maintenance work management system

    Kanai, T.; Takahashi, Y.; Takahashi, K.; Nishino, M.; Takeshige, R.

    2000-01-01

    The maintenance work management system supports the efficient drawing up of various documents for the maintenance work at nuclear power stations and the speeding up of the permission procedure. In addition, it improves the quality assurance of the safety and reliability of the maintenance work. Key merits of the system are: 1. Efficiently drawing up various documents for the maintenance work by using the stored data for the previous maintenance work and the pipe and instrument diagram (P and ID) data. 2. Supporting the management work for the completion of maintenance work safety by using the isolation information stored on the computer system. 3. Speeding up the permission procedure by electronic mail and electronic permission. 4. Displaying additional information such as the specifications of equipment, maintenance result, and maintenance plan by linking up with the database of another system. 5. Reducing the cost of hardware devices by using client/server network configurations of personal computers and a personal computer server. (author)

  1. Unsurfaced Road Maintenance Management

    1992-12-01

    This draft manual describes an unsurfaced road maintenance management system for use on military installations. This system is available in either a manual or computerized mode (Micro PAVER). The maintenance standards prescribed should protect Govern...

  2. Winter maintenance performance measure.

    2016-01-01

    The Winter Performance Index is a method of quantifying winter storm events and the DOTs response to them. : It is a valuable tool for evaluating the States maintenance practices, performing post-storm analysis, training : maintenance personnel...

  3. NPP Information Model as an Innovative Approach to End-to-End Lifecycle Management of the NPP and Nuclear Knowledge Management Proven in Russia

    Tikhonovsky, V.; Kanischev, A.; Kononov, V.; Salnikov, N.; Shkarin, A.; Dorobin, D.

    2016-01-01

    Full text: Managing engineering data for an industrial facility, including integration and maintenance of all engineering and technical data, ensuring fast and convenient access to that information and its analysis, proves to be necessary in order to perform the following tasks: 1) to increase economic efficiency of the plant during its lifecycle, including the decommissioning stage; 2) to ensure strict adherence to industrial safety requirements, radiation safety requirements (in case of nuclear facilities) and environmental safety requirements during operation (including refurbishment and restoration projects) and decommissioning. While performing tasks 1) and 2), one faces a range of challenges: 1. A huge amount of information describing the plant configuration. 2. Complexity of engineering procedures, step-by-step commissioning and significant geographical distribution of industrial infrastructure. 3. High importance of plant refurbishment projects. 4. The need to ensure comprehensive knowledge transfer between different generations of operational personnel and, which is especially important for the nuclear energy industry, between the commissioning personnel generations. NPP information model is an innovative method of NPP knowledge management throughout the whole plant lifecycle. It is an integrated database with all NPP technical engineering information (design, construction, operation, diagnosing, maintenance, refurbishment). (author

  4. Influence Diagrams for Optimal Maintenance Planning

    Friis-Hansen, Andreas

    2000-01-01

    Over the last two decades Bayesian networks and influence diagrams have received notable attention within the field of artificial intelligence and expert systems. During the last few years the technology has been further developed for problem solving within other engineering fields. The objective...... of this study is to present a conceptual bayesian network model for probabilistic prediction of fatigue crack growth in welded steel tubes. It is shown that despite discretization of the variable domain, the prediction is in good agreement with results obtained by the well-established structural reliability...

  5. Competence within Maintenance

    Nerland, Annette Smørholm

    2010-01-01

    Maintenance can be a contributing factor to unwanted events, as well as desired events and states. Human competence can be defined as the ability to perform a specific task, action or function successfully, and is therefore a key factor to proper execution of maintenance tasks. Hence,maintenance will have negative consequences if done wrong, and give positive results when done right. The purpose of this report is to study the many aspects of maintenance competence. Endeavoring to improve ...

  6. Numerical Optimization Using Desktop Computers

    1980-09-11

    geophysical, optical and economic analysis to compute a life-cycle cost for a design with a stated energy capacity. NISCO stands for NonImaging ...more efficiently by nonimaging optical systems than by conventional image forming systems. The methodology of designing optimized ronimaging systems...compound parabolic concentrating iWelford, W. T. and Winston, R., The Optics of Nonimaging Concentrators, Light and Solar Energy, p. ix, Academic

  7. Asphalt in Pavement Maintenance.

    Asphalt Inst., College Park, MD.

    Maintenance methods that can be used equally well in all regions of the country have been developed for the use of asphalt in pavement maintenance. Specific information covering methods, equipment and terminology that applies to the use of asphalt in the maintenance of all types of pavement structures, including shoulders, is provided. In many…

  8. Dukovany NPP maintenance management

    Siegel, F.

    2005-01-01

    Maintenance planning and management for the technological equipment of the Dukovany NPP are described. A Maintenance Control and Evaluation System has been developed and is in use to help manage the complex maintenance issue. Practical examples of outputs of the System, with a comprehensive use of the cost, reliability and safety related data, are presented. (author)

  9. A systematic approach to safety case maintenance

    Kelly, T.P.; McDermid, J.A.

    2001-01-01

    A crucial aspect of safety case management is the ongoing maintenance of the safety argument through life. Throughout the operational life of any system, changing regulatory requirements, additional safety evidence and a changing design can challenge the corresponding safety case. In order to maintain an accurate account of the safety of the system, all such challenges must be assessed for their impact on the original safety argument. This is increasingly being recognised by many safety standards. However, many safety engineers are experiencing difficulties with safety case maintenance at present, the prime reason being that they do not have a systematic and methodical approach by which to examine the impact of change on safety argument. The size and complexity of safety arguments and evidence being presented within safety cases is increasing. Nowhere is this more apparent than for Electrical, Electronic and Programmable Electronic systems attempting to comply with the requirements and recommendations of software and hardware safety standards such as and UK Defence Standards 00-54 [MoD. 00-54 Requirements of Safety Related Electronic Hardware in Defence Equipment. Ministry of Defence, Interim Defence Standard, 1999], 00-55 []. However, this increase in safety case complexity exacerbates problems of comprehension and maintainability later on in the system lifecycle. This paper defines and describes a tool-supported process, based upon the principles of goal structuring, that attempts to address these difficulties through facilitating the systematic impact assessment of safety case challenges

  10. Operation and maintenance of offshore wind farms

    Petersen, Kristian R.; Madsen, Erik Skov; Bilberg, Arne

    The offshore wind industry is booming and larger, more efficient wind-turbines have constantly been introduced into the market. However, research within the field of the operation and maintenance (O&M) of offshore wind farms is limited as the field is still immature. In this paper, two current ma...... maintenance models - RCM and TPM - are discussed in this context. Furthermore, through a case study, the paper looks into Modularization and SSLP, as these concepts can be utilized to optimize maintenance. This is a new approach for the offshore wind industry....

  11. Impacts of building information modeling on facility maintenance management

    Ahamed, Shafee; Neelamkavil, Joseph; Canas, Roberto [Centre for Computer-assisted Construction Technologies, National Research Council of Canada, London, Ontario (Canada)

    2010-07-01

    Building information modeling (BIM) is a digital representation of the physical and functional properties of a building; it has been used by construction professionals for a long time and stakeholders are now using it in different aspects of the building lifecycle. This paper intends to present how BIM impacts the construction industry and how it can be used for facility maintenance management. The maintenance and operations of buildings are in most cases still managed through the use of drawings and spreadsheets although life cycle costs of a building are significantly higher than initial investment costs; thus, the use of BIM could help in achieving a higher efficiency and so important benefits. This study is part of an ongoing research project, the nD modeling project, which aims at predicting building energy consumption with better accuracy.

  12. Assessing the social impacts of the biofuel lifecycle

    Jørgensen, Andreas; Hauschild, Michael Zwicky

    In order to assess the social impacts of the biofuel lifecycle, Social Life Cycle Assessment (SLCA) may be a promising tool. However, as this review study points out, several problems are still to be solved. SLCA can be defined as a tool for assessing a product’s or service’s total impact on human...... health and well-being throughout its life cycle. During the recent years several different approaches towards SLCA have been developing. This review reveals a broad variety in how the SLCAs address all methodological steps. One of the main differences is in the choice and formulation of social indicators....... The indicators address a wide variety of issues; some approaches focus on impacts created in the very close proximity of the processes included in the product system, whereas others focus on the more remote societal consequences. The perception of social impacts is thus very varying. An assessment focussing...

  13. Stochastic cost estimating in repository life-cycle cost analysis

    Tzemos, S.; Dippold, D.

    1986-01-01

    The conceptual development, the design, and the final construction and operation of a nuclear repository span many decades. Given this lengthy time frame, it is quite challenging to obtain a good approximation of the repository life-cycle cost. One can deal with this challenge by using an analytic method, the method of moments, to explicitly assess the uncertainty of the estimate. A series expansion is used to approximate the uncertainty distribution of the cost estimate. In this paper, the moment methodology is derived and is illustrated through a numerical example. The range of validity of the approximation is discussed. The method of moments is compared to the traditional stochastic cost estimating methods and found to provide more and better information on cost uncertainty. The tow methods converge to identical results as the number of convolved variables increases and approaches the range where the central limit theorem is valid

  14. Life-cycle cost trade studies for hardness assurance

    Millward, D.G.

    1996-01-01

    Based on hardness assurance (HA) cost trade studies conducted on a low-cost/high-volume tactical military system with moderate radiation environments, conventional strategies for design hardening and HA can result in higher life-cycle costs (LCC) than alternate approaches. The trade studies used variables designed to investigate LCC as a function of several critical parameters, including semiconductor procurement option, system quantity, HA testing option,a nd other variables. An LCC model and sample problem are included to illustrate the key results. Following the results of the trade studies, limitations of the simplified cost model are presented, the relationship of these results to current procurement practices are discussed, and the application of the results to modern military and commercial systems is discussed

  15. The life-cycle research productivity of mathematicians and scientists.

    Diamond, A M

    1986-07-01

    Declining research productivity with age is implied by economic models of life-cycle human capital investment but is denied by some recent empirical studies. The purpose of the present study is to provide new evidence on whether a scientist's output generally declines with advancing age. A longitudinal data set has been compiled for scientists and mathematicians at six major departments, including data on age, salaries, annual citations (stock of human capital), citations to current output (flow of human capital), and quantity of current output measured both in number of articles and in number of pages. Analysis of the data indicates that salaries peak from the early to mid-60s, whereas annual citations appear to peak from age 39 to 89 for different departments with a mean age of 59 for the 6 departments. The quantity and quality of current research output appear to decline continuously with age.

  16. Life-cycle analysis of product integrated polymer solar cells

    Espinosa Martinez, Nieves; García-Valverde, Rafael; Krebs, Frederik C

    2011-01-01

    A life cycle analysis (LCA) on a product integrated polymer solar module is carried out in this study. These assessments are well-known to be useful in developmental stages of a product in order to identify the bottlenecks for the up-scaling in its production phase for several aspects spanning from...... economics through design to functionality. An LCA study was performed to quantify the energy use and greenhouse gas (GHG) emissions from electricity use in the manufacture of a light-weight lamp based on a plastic foil, a lithium-polymer battery, a polymer solar cell, printed circuitry, blocking diode......, switch and a white light emitting semiconductor diode. The polymer solar cell employed in this prototype presents a power conversion efficiency in the range of 2 to 3% yielding energy payback times (EPBT) in the range of 1.3–2 years. Based on this it is worthwhile to undertake a life-cycle study...

  17. A genetic algorithm solution for a nuclear power plant risk-cost maintenance model

    Tong Jiejuan; Mao Dingyuan; Xue Dazhi

    2004-01-01

    Reliability Centered Maintenance (RCM) is one of the popular maintenance optimization methods according to certain kinds of priorities. Traditional RCM usually analyzes and optimizes the maintenance strategy from the viewpoint of component instead of the whole maintenance program impact. Research presented in this paper is a pilot study using PSA techniques in RCM. How to reflect the effect on component unavailability by the maintenance activities such as surveillance testing and preventive maintenance in PSA model is discussed firstly. Based on the discussion, a maintenance risk-cost model is established for global maintenance optimization in a nuclear power plant, and a genetic algorithm (GA) is applied to solve such a model to get the global optimized maintenance strategy. Finally, the result got from a simple test case based on a risk-cost model consisting of 10 components is presented

  18. Product Lifecycle Management and the Quest for Sustainable Space Explorations

    Caruso, Pamela W.; Dumbacher, Daniel L.

    2010-01-01

    Product Lifecycle Management (PLM) is an outcome of lean thinking to eliminate waste and increase productivity. PLM is inextricably tied to the systems engineering business philosophy, coupled with a methodology by which personnel, processes and practices, and information technology combine to form an architecture platform for product design, development, manufacturing, operations, and decommissioning. In this model, which is being implemented by the Engineering Directorate at the National Aeronautics and Space Administration's (NASA's) Marshall Space Flight Center, total lifecycle costs are important variables for critical decision-making. With the ultimate goal to deliver quality products that meet or exceed requirements on time and within budget, PLM is a powerful concept to shape everything from engineering trade studies and testing goals, to integrated vehicle operations and retirement scenarios. This paper will demonstrate how the Engineering Directorate is implementing PLM as part of an overall strategy to deliver safe, reliable, and affordable space exploration solutions. It has been 30 years since the United States fielded the Space Shuttle. The next generation space transportation system requires a paradigm shift such that digital tools and knowledge management, which are central elements of PLM, are used consistently to maximum effect. The outcome is a better use of scarce resources, along with more focus on stakeholder and customer requirements, as a new portfolio of enabling tools becomes second nature to the workforce. This paper will use the design and manufacturing processes, which have transitioned to digital-based activities, to show how PLM supports the comprehensive systems engineering and integration function. It also will go through a launch countdown scenario where an anomaly is detected to show how the virtual vehicle created from paperless processes will help solve technical challenges and improve the likelihood of launching on schedule

  19. Partnering With Patients in the Development and Lifecycle of Medicines

    Anderson, James; Boutin, Marc; Dewulf, Lode; Geissler, Jan; Johnston, Graeme; Joos, Angelika; Metcalf, Marilyn; Regnante, Jeanne; Sargeant, Ifeanyi; Schneider, Roslyn F.; Todaro, Veronica; Tougas, Gervais

    2015-01-01

    The purpose of medicines is to improve patients' lives. Stakeholders involved in the development and lifecycle management of medicines agree that more effective patient involvement is needed to ensure that patient needs and priorities are identified and met. Despite the increasing number and scope of patient involvement initiatives, there is no accepted master framework for systematic patient involvement in industry-led medicines research and development, regulatory review, or market access decisions. Patient engagement is very productive in some indications, but inconsistent and fragmentary on a broader level. This often results in inefficient drug development, increasing evidence requirements, lack of patient-centered outcomes that address unmet medical needs and facilitate adherence, and consequently, lack of required therapeutic options and high costs to society and involved parties. Improved patient involvement can drive the development of innovative medicines that deliver more relevant and impactful patient outcomes and make medicine development faster, more efficient, and more productive. It can lead to better prioritization of early research; improved resource allocation; improved trial protocol designs that better reflect patient needs; and, by addressing potential barriers to patient participation, enhanced recruitment and retention. It may also improve trial conduct and lead to more focused, economically viable clinical trials. At launch and beyond, systematic patient involvement can also improve the ongoing benefit-risk assessment, ensure that public funds prioritize medicines of value to patients, and further the development of the medicine. Progress toward a universal framework for patient involvement requires a joint, precompetitive, and international approach by all stakeholders, working in true partnership to consolidate outputs from existing initiatives, identify gaps, and develop a comprehensive framework. It is essential that all stakeholders

  20. Multidimensional simulations of hydrides during fuel rod lifecycle

    Stafford, D.S.

    2015-01-01

    In light water reactor fuel rods, waterside corrosion of zirconium-alloy cladding introduces hydrogen into the cladding, where it is slightly soluble. When the solubility limit is reached, the hydrogen precipitates into crystals of zirconium hydride which decrease the ductility of the cladding and may lead to cladding failure during dry storage or transportation events. The distribution of the hydride phase and the orientation of the crystals depend on the history of the spatial temperature and stress profiles in the cladding. In this work, we have expanded the existing hydride modeling capability in the BISON fuel performance code with the goal of predicting both global and local effects on the radial, azimuthal and axial distribution of the hydride phase. We compare results from 1D simulations to published experimental data. We demonstrate the new capability by simulating in 2D a fuel rod throughout a lifecycle that includes irradiation, short-term storage in the spent fuel pool, drying, and interim storage in a dry cask. Using the 2D simulations, we present qualitative predictions of the effects of the inter-pellet gap and the drying conditions on the growth of a hydride rim. - Highlights: • We extend BISON fuel performance code to simulate lifecycle of fuel rods. • We model hydrogen evolution in cladding from reactor through dry storage. • We validate 1D simulations of hydrogen evolution against experiments. • We show results of 2D axisymmetric simulations predicting hydride formation. • We show how our model predicts formation of a hydride rim in the cladding.