Single-stage Kanban system with deterioration failures and condition-based preventive maintenance

International Nuclear Information System (INIS)

Xanthopoulos, A.S.; Koulouriotis, D.E.; Botsaris, P.N.

2015-01-01

Despite the fact that the fields of pull type production control policies and condition-based preventive maintenance have much in common contextually, they have evolved independently up to now. In this investigation, an attempt is made to bridge the gap between these two branches of knowledge by introducing the single-stage Kanban system with deterioration failures and condition-based preventive maintenance. The formalism of continuous time Markov chains is used to model the system and expressions for eight performance metrics are derived. Two important, from a managerial perspective, constrained optimization problems for the proposed model are defined where the objective is the simultaneous optimization of the Kanban policy, the preventive maintenance policy and the inspection schedule under conflicting performance criteria. Multiple instances of each optimization problem are solved by means of the augmented Lagrangian genetic algorithm. The results from the optimization trials coupled by the results from extensive numerical examples facilitate the thorough investigation of the system’s behaviour. - Highlights: • Kanban system with deterioration failures and preventive maintenance is introduced. • The system is modeled as a continuous time Markov chain. • Expressions for eight performance metrics are derived. • The behavior of the system is studied through numerical examples. • Optimization results for selected performance metrics are presented

Optimization of the preventive maintenance plan of a series components system

Energy Technology Data Exchange (ETDEWEB)

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.

Design of preventive maintenance system using the reliability engineering and maintenance value stream mapping methods in PT. XYZ

Science.gov (United States)

Sembiring, N.; Panjaitan, N.; Angelita, S.

2018-02-01

PT. XYZ is a company owned by non-governmental organizations engaged in the field of production of rubber processing becoming crumb rubber. Part of the production is supported by some of machines and interacting equipment to achieve optimal productivity. Types of the machine that are used in the production process are Conveyor Breaker, Breaker, Rolling Pin, Hammer Mill, Mill Roll, Conveyor, Shredder Crumb, and Dryer. Maintenance system in PT. XYZ is corrective maintenance i.e. repairing or replacing the engine components after the crash on the machine. Replacement of engine components on corrective maintenance causes the machine to stop operating during the production process is in progress. The result is in the loss of production time due to the operator must replace the damaged engine components. The loss of production time can impact on the production targets which were not reached and lead to high loss costs. The cost for all components is Rp. 4.088.514.505. This cost is really high just for maintaining a Mill Roll Machine. Therefore PT. XYZ is needed to do preventive maintenance i.e. scheduling engine components and improving maintenance efficiency. The used methods are Reliability Engineering and Maintenance Value Stream Mapping (MVSM). The needed data in this research are the interval of time damage to engine components, opportunity cost, labor cost, component cost, corrective repair time, preventive repair time, Mean Time To Opportunity (MTTO), Mean Time To Repair (MTTR), and Mean Time To Yield (MTTY). In this research, the critical components of Mill Roll machine are Spier, Bushing, Bearing, Coupling and Roll. Determination of damage distribution, reliability, MTTF, cost of failure, cost of preventive, current state map, and future state map are done so that the replacement time for each critical component with the lowest maintenance cost and preparation of Standard Operation Procedure (SOP) are developed. For the critical component that has been

Study on application of safety checklist in preventive maintenance activities

International Nuclear Information System (INIS)

Shi Jin; Chen Song; Liu Jingquan

2013-01-01

The paper describes the principles and the characteristics of safety checklist as a risk evaluation method. Examples of application of safety checklists to preventive maintenance activities such as criteria comparison and checkup items in place in nuclear power plants are illustrated in details with issues appeared in the checklist establishment. Checklist has a good application in the RCM analysis or in the actual preventive maintenance program for Chashma Nuclear Power Plant indicated by concrete instances. In the light of safety checklist which is used to sustain preventive maintenance as a simple and applicable risk analysis approach, we can get deep knowledge of risks of nuclear power plant to perfect preventive maintenance activities. (authors)

Imperfect Preventive Maintenance Model Study Based On Reliability Limitation

Directory of Open Access Journals (Sweden)

Zhou Qian

2016-01-01

Full Text Available Effective maintenance is crucial for equipment performance in industry. Imperfect maintenance conform to actual failure process. Taking the dynamic preventive maintenance cost into account, the preventive maintenance model was constructed by using age reduction factor. The model regards the minimization of repair cost rate as final target. It use allowed smallest reliability as the replacement condition. Equipment life was assumed to follow two parameters Weibull distribution since it was one of the most commonly adopted distributions to fit cumulative failure problems. Eventually the example verifies the rationality and benefits of the model.

Preventive Maintenance. FMO: Fundamentals of Machine Operation. Third Edition.

Science.gov (United States)

Hathaway, Louis

This text is intended to provide students with basic information on conducting preventive maintenance on agricultural machinery. The following topics are covered in the individual chapters: the importance of preventive maintenance and recommended service intervals; engine intake and exhaust systems (air cleaners, turbochargers, intake and exhaust…

Integrated preventive maintenance and production decisions for imperfect processes

International Nuclear Information System (INIS)

Nourelfath, Mustapha; Nahas, Nabil; Ben-Daya, Mohamed

2016-01-01

This paper integrates production, maintenance, and quality for an imperfect process in a multi-period multi-product capacitated lot-sizing context. The production system is modeled as an imperfect machine, whose the status is considered to be either in-control or out-of-control. When the machine is out of control, it produces a fraction of nonconforming items. During each period, this machine is inspected and imperfect preventive maintenance activities are simultaneously performed to reduce its age, proportional to the preventive maintenance level. The objective is to minimize the total cost, while satisfying the demand for all products. Our optimization model allows for a joint selection of the optimal values of production plan, and the maintenance policy, while taking into account quality related costs. A solution algorithm is developed and illustrative numerical examples are presented. It is found that the increase in PM level leads to reductions in quality control costs. Furthermore, if the cost of performing PM is high to the point where it is not compensated for by reductions in the quality related costs, then performing PM is not justifiable. Finally, using non-periodic preventive maintenance with the possibility of different preventive maintenance levels may result in an improvement of the total cost. - Highlights: • We integrate production, maintenance, and quality. • We evaluate all the expected costs. • Our model allows for a joint selection of the optimal values. • A solution algorithm is developed. • Increasing PM level will decrease quality control costs.

MINIMASI BIAYA PERAWATAN DENGAN MENGGUNAKAN METODE PREVENTIVE MAINTENANCE POLICY

Directory of Open Access Journals (Sweden)

Much Djunaidi

2012-12-01

Full Text Available PT. Primatexco Indonesia merupakan perusahaan tekstil dengan produk benang tenun, kain, printing, dan waste. Di PT. Primatexco Indonesia terdapat bagian blowing yang bertugas menyuplai bahan baku untuk proses produksi. Artikel ini membahas mengenai alternatif jadwal perbaikan maupun perawatan dengan biaya terkecil untuk komponen mesin blowing. Dengan menghitung biaya perawatan untuk repair policy dan dibandingkan dengan biaya preventive maintenance policy, maka akan didapatkan jadwal perbaikan maupun perawatan yang optimal. Dari hasil perhitungan, diusulkan jadwal perawatan mengikuti kebijakan repair untuk kerusakan komponen klasifikasi A. Untuk kerusakan komponen klasifikasi B diterapkan kebijakan preventive maintenance setiap 5 bulan. Dan untuk kerusakan komponen klasifikasi C diterapkan kebijakan preventive maintenance setiap 7 bulan.

Development of maintenance procedure for plate type heat exchanger taking into account preventing radioactive contamination

International Nuclear Information System (INIS)

Terai, Kensuke; Someki, Hiroyuki; Ueda, Yuya

2017-01-01

In Japanese pressurized water reactors (PWR), heat loads of spent fuel pools (SFP) is increasing due to rising spent fuels and use of mixed oxide (MOX) fuels. Therefore, SFP cooling capacities are necessary to be enhanced, and replacement of SFP coolers or installation of additional coolers is needed. On the other hand, installation spaces of SFP coolers are limited in existing buildings. Therefore, plate type heat exchangers which can be designed to be compact because of the high heat efficiency have often been adopted for SFP coolers instead of shell and tube type heat exchangers in general use. Plate type heat exchangers have to be overhauled periodically for inspection and gasket replacement. However, in plate type SFP coolers, radioactive SFP water and non-radioactive component cooling water (CCW) alternately run through between each plate. Thus there is a concern that the CCW system may be contaminated by radioactive materials from the SFP water during overhaul of the SFP cooler. In order to solve this problem, we have developed the maintenance procedure of the plate type SFP coolers to prevent CCW side contamination by coating the contaminated surfaces with strippable paint prior to disassembly. Before applying this developed maintenance procedure to actual equipment, we have performed the following verification tests. (1) Confirmation of fundamental characteristics for strippable paint. Firstly, we selected both water-based and solvent-based strippable paints. Secondly, we tested and confirmed the detachability and the drying time of the selected strippable paints respectively. Moreover we also confirmed that the selected strippable paints are appropriate materials from the viewpoint of chemical composition restriction of consumable materials used in nuclear power plant. (2) Confirmation of workability for paint filling, drying and peeling off. The strippable paints need to be peeled off after filling into plate type heat exchanger and draining

Preventative maintenance of straddle carriers

Directory of Open Access Journals (Sweden)

Si Li

2015-04-01

Objectives: The purpose of this industry-driven study is to model preventative maintenance (PM influences on the operational effectiveness of straddle carriers. Method: The study employs historical data consisting of 21 273 work orders covering a 27-month period. Two models are developed, both of which forecast influences of PM regimes for different types of carrier. Results: The findings of the study suggest that the reliability of the straddle fleet decreases with increased intervals of PM services. The study also finds that three factors – namely resources, number of new straddles, and the number of new lifting work centres – influence the performances of straddles. Conclusion: The authors argue that this collaborative research exercise makes a significant contribution to existing supply chain management literature, particularly in the area of operations efficiency. The study also serves as an avenue to enhance relevant management practice.

Optimal preventive maintenance and repair policies for multi-state systems

International Nuclear Information System (INIS)

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

Preventive maintenance basis: Volume 31 -- Relays -- timing. Final report

International Nuclear Information System (INIS)

Worledge, D.; Hinchcliffe, G.

1998-07-01

US nuclear power plants are implementing preventive maintenance (PM) tasks with little documented basis beyond fundamental vendor information to support the tasks or their intervals. The Preventive Maintenance Basis project provides utilities with the technical basis for PM tasks and task intervals associated with 40 specific components such as valves, electric motors, pumps, and HVAC equipment. This document provides a program of preventive maintenance tasks suitable for application to timing relays. The PM tasks that are recommended provide a cost-effective way to intercept the causes and mechanisms that lead to degradation and failure. They can be used in conjunction with material from other sources, to develop a complete PM program or to improve an existing program

Preventive maintenance basis: Volume 30 -- Relays -- control. Final report

International Nuclear Information System (INIS)

Worledge, D.; Hinchcliffe, G.

1998-07-01

US nuclear power plants are implementing preventive maintenance (PM) tasks with little documented basis beyond fundamental vendor information to support the tasks or their intervals. The Preventive Maintenance Basis project provides utilities with the technical basis for PM tasks and task intervals associated with 40 specific components such as valves, electric motors, pumps, and HVAC equipment. This document provides a program of preventive maintenance tasks suitable for application to control relays. The PM tasks that are recommended provide a cost-effective way to intercept the causes and mechanisms that lead to degradation and failure. They can be used in conjunction with material from other sources, to develop a complete PM program or to improve an existing program

Preventive maintenance technology for nuclear power stations

International Nuclear Information System (INIS)

Miyazawa, Tatsuo

1992-01-01

With the increase of the number of nuclear power plants in operation and the number of years of operation, the improvement of reliability and the continuation of safe operation have become more important, and the expectation for preventive maintenance technology has also heightened. The maintenance of Japanese nuclear power plants is based on the time schedule maintenance mainly by the regular inspection carried out every year, but the monitoring of the conditions of various machinery and equipment in operation has been performed widely. In this report, the present state of checkup and inspection technologies and the monitoring and diagnostic technologies for operational condition, which are the key technologies of preventive maintenance, are described. As the checkup and inspection technologies, ultrasonic flow detection technology, phased array technology, Amplituden und Laufzeit Orts Kurven method and X-ray CT, and as the monitoring and diagnostic technologies for operational condition, the diagnosis support system for BWR plants 'PLADIS', those for rotary machines, those for turbogenerators, those for solenoid valves, the mechanization of patrol works and the systematizing technology are reported. (K.I.)

Two Different Maintenance Strategies in the Hospital Environment: Preventive Maintenance for Older Technology Devices and Predictive Maintenance for Newer High-Tech Devices.

Science.gov (United States)

Sezdi, Mana

2016-01-01

A maintenance program generated through the consideration of characteristics and failures of medical equipment is an important component of technology management. However, older technology devices and newer high-tech devices cannot be efficiently managed using the same strategies because of their different characteristics. This study aimed to generate a maintenance program comprising two different strategies to increase the efficiency of device management: preventive maintenance for older technology devices and predictive maintenance for newer high-tech devices. For preventive maintenance development, 589 older technology devices were subjected to performance verification and safety testing (PVST). For predictive maintenance development, the manufacturers' recommendations were used for 134 high-tech devices. These strategies were evaluated in terms of device reliability. This study recommends the use of two different maintenance strategies for old and new devices at hospitals in developing countries. Thus, older technology devices that applied only corrective maintenance will be included in maintenance like high-tech devices.

Flexibility configurations and preventive maintenance impact on job-shop manufacturing systems

Directory of Open Access Journals (Sweden)

Paolo Renna

2017-03-01

Full Text Available Manufacturing systems need to be able to work under the dynamic and uncertain production environment. Machine and routing flexibility combined with preventive maintenance actions can improve the performance of the manufacturing systems under dynamic conditions. This paper evaluates different levels of machine and routing flexibility combined with different degrees of preventive maintenance policy. The performance measures considered are throughput, work in process and throughput. The performance measures are compared with a system without any flexibility and no preventive maintenance actions. Different levels of flexibility and preventive maintenance actions are examined under a simulation environment. The simulation results highlight more important factors for the performance measures and the best combination of the factors to improve the performance.

Cost effectiveness of the MDOT preventive maintenance program.

Science.gov (United States)

2013-04-01

The Michigan Department of Transportations (MDOT) pavement preservation program dates back to 1992. MDOTs pavement preservation strategy is primarily implemented through its capital preventive maintenance (CPM) program, in which preventive main...

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

International Nuclear Information System (INIS)

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.

Application of preventive maintenance planning in a parquet ...

African Journals Online (AJOL)

In this study, the process of a parquet enterprise's transition to preventive maintenance which has been implementing maintenance technique in case of breakdown was investigated. During that transition process, follow up forms for maintenance–repair, breakdown and spare parts were prepared and the implementation ...

MPGV: An expert system for the preventive maintenance of the vapor generators in a PWR type reactor

International Nuclear Information System (INIS)

Castelanu, L.

1990-01-01

The characteristics and the architecture of the expert system designed for assisting the preventive maintenance of vapor generators are described. The main objectives of the system are: to optimize the inspection plans, to assess breakdown risks, to propose solutions and to organize maintenance operations. The expert system allows the accurate evaluation of risks concerning the development of an application. However, the experience demonstrates that a cost-benefit analysis not accurate enough induces errors in the expert system applications [fr

Preventive maintenance-A countermeasure to plant aging

International Nuclear Information System (INIS)

Hlubek, W.

1985-01-01

The aging of power plants is caused by manifold and different influences. For instance, mechanical and thermal stress, radiation exposure, denting or wastage can considerably affect the aging of plant components and thus cause premature failures of components. In this presentation, the term 'Plant Aging' in nuclear power plants is to be understood more comprehensively than wear on components and material fatigue. In addition, nuclear power plants are to be adjusted to the advancing state of the science and technology (state-of-the-art) in order to guarantee safe operation at all times. The preventive maintenance - as a countermeasure to plant aging - comprises the systematic checks and servicing of the plant systems in operation and follows aging by inspection and tests. Experience with Rheinisch-Westfaelisches Elektrizitaetswerk AG (RWE) preventive maintenance program at the Biblis NNP (1300 MW, PWR) is discussed. The concept of an 'Integrated Maintenance System' as a means to avoid 'Plant Aging' is presented

RCM optimization of a system under both preventive and corrective maintenance

International Nuclear Information System (INIS)

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)

An integrated production, inventory and preventive maintenance model for a multi-product production system

International Nuclear Information System (INIS)

Liu, Xuejuan; Wang, Wenbin; Peng, Rui

2015-01-01

This paper considers a production system that can produce multiple products alternately. Products go through the system in a sequence and a complete run of all products forms a production cycle. An integrated production, inventory and preventive maintenance model is constructed, which is characterized by the delay-time concept. Two different situations are studied based on whether the unqualified products and downtime caused by the failures of the system, set-up and preventive maintenance can be ignored or not. Three cases are considered for each situation, depending on the position of the preventive maintenance epochs: the first case, where preventive maintenance is carried out at the end of each production cycle; the second case, where preventive maintenance is carried out at each set-up time of the products; and the third case, where preventive maintenance is carried out at some set-up times only, since it may not always be optimal to carry out preventive maintenance at the end of the production cycle or at each set-up time. The modeling objectives are to find the optimal number of production cycles per year and the optimal position of preventive maintenance that will maximize the expected profit per unit time. Numerical examples, using real data, are presented to illustrate the model. - Highlights: • We propose an integrated economic production quantity and preventive maintenance model. • The situation that multiple products are produced on the same system alternately is studied. • Two situations are studied based on whether the downtime and the product quality can be ignored or not. • We use enumeration method and analytical method to select the optimal preventive maintenance policy, respectively. • We use the delay-time concept to model the preventive maintenance policy

Optimum policies for a system with general imperfect maintenance

International Nuclear Information System (INIS)

Sheu, S.-H.; Lin, Y.-B.; Liao, G.-L.

2006-01-01

This study considers periodic preventive maintenance policies, which maximizes the availability of a repairable system with major repair at failure. Three types of preventive maintenance are performed, namely: imperfect preventive maintenance (IPM), perfect preventive maintenance (PPM) and failed preventive maintenance (FPM). The probability that preventive maintenance is perfect depends on the number of imperfect maintenances conducted since the previous renewal cycle, and the probability that preventive maintenance remains imperfect is not increasing. The optimum preventive maintenance time that maximizes availability is derived. Various special cases are considered. A numerical example is given

Preventive and corrective maintenance for MINT EPS 3000 electron beam machine

International Nuclear Information System (INIS)

Siti Aiasah Hashim; Shaari Jahar

2005-01-01

Preventive and corrective maintenance of a high energy electron is to ensure that the machine would not fail during operation. MINT's EPS 3000 electron beam machine has been in operation for almost 12 years. Throughout those years, events relating to scheduled overhauls and unscheduled corrective maintenance had provided invaluable experience in the form of informal maintenance training to the operators. With the implementation of ISO 9001:2000 Quality Management System at the facility, the preventive and corrective maintenance program is becoming more structured and orderly. Collected maintenance data shall be used to initiate continual improvement activities in the facility.This paper describes MINT-ALURTRON's 12 years experience in providing maintenance work for the EPS 3000. (Author)

Reliability-based maintenance evaluations and standard preventive maintenance programs

International Nuclear Information System (INIS)

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

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

International Nuclear Information System (INIS)

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

Wind turbine blade life-time assessment model for preventive planning of operation and maintenance

DEFF Research Database (Denmark)

Florian, Mihai; Sørensen, John Dalsgaard

2014-01-01

Out of the total wind turbine failure events, blade damage accounts for a substantial part, with some studies estimating it at around 23%. Current operation and maintenance (O&M) practices typically make use of corrective type maintenance as the basic approach, implying high costs for repair...... of information on the blades structural health to the decision maker. Further, inspections of the blades are often performed in connection with service. In light of the obtained information, a preventive type of maintenance becomes feasible, with the potential of predicting the blades remaining life to support O......&M decisions for avoiding major failure events. The present paper presents a fracture mechanics based model for estimating the remaining life of a wind turbine blade, focusing on the crack propagation in the blades adhesive joints. A generic crack propagation model is built in Matlab based on a Paris law...

Wind Turbine Blade Life-Time Assessment Model for Preventive Planning of Operation and Maintenance

DEFF Research Database (Denmark)

Florian, Mihai; Sørensen, John Dalsgaard

2015-01-01

Out of the total wind turbine failure events, blade damage accounts for a substantial part, with some studies estimating it at around 23%. Current operation and maintenance (O&M) practices typically make use of corrective type maintenance as the basic approach, implying high costs for repair...... of information on the blades structural health to the decision maker. Further, inspections of the blades are often performed in connection with service. In light of the obtained information, a preventive type of maintenance becomes feasible, with the potential of predicting the blades remaining life to support O......&M decisions for avoiding major failure events. The present paper presents a fracture mechanics based model for estimating the remaining life of a wind turbine blade, focusing on the crack propagation in the blades adhesive joints. A generic crack propagation model is built in Matlab based on a Paris law...

Preventive maintenance basis: Volume 19 -- HVAC -- chillers and compressors. Final report

International Nuclear Information System (INIS)

Worledge, D.; Hinchcliffe, G.

1997-12-01

US nuclear power plants are implementing preventive maintenance (PM) tasks with little documented basis beyond fundamental vendor information to support the tasks or their intervals. The Preventive Maintenance Basis project provides utilities with the technical basis for PM tasks and task intervals associated with 40 specific components such as valves, electric motors, pumps, and HVAC equipment. This document provides a program of preventive maintenance tasks suitable for application to HVAC -- Chillers and Compressors. The PM tasks that are recommended provide a cost-effective way to intercept the causes and mechanisms that lead to degradation and failure. They can be used in conjunction with material from other sources, to develop a complete PM program or to improve an existing program

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

Science.gov (United States)

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.

Two Different Maintenance Strategies in the Hospital Environment: Preventive Maintenance for Older Technology Devices and Predictive Maintenance for Newer High-Tech Devices

OpenAIRE

Sezdi, Mana

2016-01-01

A maintenance program generated through the consideration of characteristics and failures of medical equipment is an important component of technology management. However, older technology devices and newer high-tech devices cannot be efficiently managed using the same strategies because of their different characteristics. This study aimed to generate a maintenance program comprising two different strategies to increase the efficiency of device management: preventive maintenance for older tec...

Preventive maintenance basis: Volume 37 -- Main turbine EHC hydraulics. Final report

International Nuclear Information System (INIS)

Worledge, D.; Hinchcliffe, G.

1998-11-01

US nuclear power plants are implementing preventive maintenance (PM) tasks with little documented basis beyond fundamental vendor information to support the tasks or their intervals. The Preventive Maintenance Basis project provides utilities with the technical basis for PM tasks and task intervals associated with 40 specific components such as valves, electric motors, pumps, and HVAC equipment. This document provides a program of preventive maintenance tasks suitable for application to the main turbine EHC hydraulic fluid and associated components. The PM tasks that are recommended provide a cost-effective way to intercept the causes and mechanisms that lead to degradation and failure. They can be used in conjunction with material from other sources, to develop a complete PM program or to improve an existing program

Wind Turbine Blade Life-Time Assessment Model for Preventive Planning of Operation and Maintenance

Directory of Open Access Journals (Sweden)

Mihai Florian

2015-09-01

Full Text Available Out of the total wind turbine failure events, blade damage accounts for a substantial part, with some studies estimating it at around 23%. Current operation and maintenance (O&M practices typically make use of corrective type maintenance as the basic approach, implying high costs for repair and replacement activities as well as large revenue losses, mainly in the case of offshore wind farms. The recent development and evolution of condition monitoring techniques, as well as the fact that an increasing number of installed turbines are equipped with online monitoring systems, offers a large amount of information on the blades structural health to the decision maker. Further, inspections of the blades are often performed in connection with service. In light of the obtained information, a preventive type of maintenance becomes feasible, with the potential of predicting the blades remaining life to support O&M decisions for avoiding major failure events. The present paper presents a fracture mechanics based model for estimating the remaining life of a wind turbine blade, focusing on the crack propagation in the blades adhesive joints. A generic crack propagation model is built in Matlab based on a Paris law approach. The model is used within a risk-based maintenance decision framework to optimize maintenance planning for the blades lifetime.

A Planned Preventive Maintenance Program. A Handbook for Chief Business Officers and Supervisors of Maintenance with Suggestions on Maintenance for Consideration by Presidents of Higher Institutions.

Science.gov (United States)

Daniel, Clarence H.

This handbook explains planned preventive maintenance program, which is an operational system of maintenance designed to increase the effectiveness of the maintenance staff and the use of maintenance funds through efficient scheduling of inspections and follow-through of work to be performed. Sections are included for the chief administrative…

Flexibility configurations and preventive maintenance impact on job-shop manufacturing systems

OpenAIRE

Paolo Renna

2017-01-01

Manufacturing systems need to be able to work under the dynamic and uncertain production environment. Machine and routing flexibility combined with preventive maintenance actions can improve the performance of the manufacturing systems under dynamic conditions. This paper evaluates different levels of machine and routing flexibility combined with different degrees of preventive maintenance policy. The performance measures considered are throughput, work in process and throughput. The performa...

Repair and preventive maintenance technology for BWR reactor internals and piping

International Nuclear Information System (INIS)

Ootsubo, Tooru; Itou, Takashi; Sakashita, Akihiro

2009-01-01

Stress corrosion cracking of welding portion has found in many domestic and foreign BWR reactor internals and Primary Loop Recirculation piping. Also, repair and preventive maintenance technologies for SCC has been developed and/or adopted to BWRs in recent years. This paper introduces the sample of these technologies, such as seal-welding for SCC on BWR reactor internals, preventive maintenance technology for PLR piping such as Corrosion Resistant Cladding, Internal Polishing and Induction Heating Stress Improvement. These technologies are introduced on 'E-Journal of Advanced Maintenance', which is an international journal on a exclusive website of Japan Society of Maintenology. (author)

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

OpenAIRE

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 ...

Building Maintenance, Management, and Budgeting.

Science.gov (United States)

Pawsey, M. R.

1982-01-01

Australian methods and formulas for funding building maintenance and management are outlined and found to be haphazard. Discussed are: ultimate costs of deferred maintenance, major plant replacements, life cycle costing, types of maintenance programs (including full preventive maintenance), use of computer programs for planning, and organization…

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

International Nuclear Information System (INIS)

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)

Condition monitoring a key component in the preventive maintenance

International Nuclear Information System (INIS)

Isar, C.

2006-01-01

The preventive maintenance programs are necessary to ensure that nuclear safety significant equipment will function when it is supposed to. Diesel generator, pumps, motor operated valves and air operated control valves are typically operated every three months. When you drive a car, you depend on lot of sounds, the feel of the steering wheel and gauges to determine if the car is running correctly. Similarly with operating equipment for a power plant - sounds or vibration of the equipment or the gauges and test equipment indicate a problem or degradation, actions are taken to correct the deficiency. Due to safety and economical reason diagnostic and monitoring systems are of growing interest in all complex industrial production. Diagnostic systems are requested to detect, diagnose and localize faulty operating conditions at an early stage in order to prevent severe failures and to enable predictive and condition oriented maintenance. In this context it is a need for using various on-line and off-line condition monitoring and diagnostics, non-destructive inspection techniques and surveillance. The condition monitoring technique used in nuclear power plant Cernavoda are presented in this paper. The selection of components and parameters to be monitored, monitoring and diagnostics techniques used are incorporated into a preventive maintenance program. Modern measurement technique in combination with advanced computerized data processing and acquisition show new ways in the field of machine surveillance. The diagnostic capabilities of predictive maintenance technologies have increased recently year with advances made in sensor technologies. The paper will focus on the following condition monitoring technique: - oil analysis - acoustic leakage monitoring - thermography - valve diagnostics: motor operated valve, air operated valve and check valve - motor current signature - vibration monitoring and rotating machine monitoring and diagnostics For each condition monitoring

After reliability centred maintenance. Preventive maintenance living program implementation at Bruce Power

International Nuclear Information System (INIS)

Harazim, Michael L.; Ferguson, Brian J.

2003-01-01

Industrial preventive maintenance (PM) programs represent a large part of plant O and M costs. PM Optimization (PMO) projects represent an effective mechanism for identifying unnecessary PM, extending PM intervals and infusing predictive maintenance (PdM) methods. However, once optimized, what process prevents the PM program from returning to a state of disarray? This is the function of a PM living program (PMLP). In 1997, an independent performance assessment identified concerns with the applicability and effectiveness of all Ontario Power Generation, Inc. (OPGI) PM programs. In response, OPGI instituted an Integrated Maintenance Program (IMP) including Reliability Centred Maintenance (RCM) and a PMLP. It should be noted that the PMLP was developed for the 3 OPGI nuclear Sites (i.e. Bruce, Pickering, and Darlington). Effective 1 May 2001, the Bruce Site has been leased to a group of investors lead by British Energy. This paper is written in historical context and therefore refers to the Bruce Site as part of OPGI. The PMLP is made up of five elements: 1) process control, 2) change control, 3) worker feedback, 4) program performance metrics, and 5) deferral module. A PMLP software tool, originally applied to Duke Energy nuclear plants, was enhanced and customized specifically for the OPGI PMLP, and then implemented at all three of OPGI's nuclear sites. The objective of the OPGI PMLP was to: Provide processes/procedures for continual optimization of all site PM tasks, Ensure effective and timely revision of PM tasks in the work management system, Ensure PM tasks remain applicable/effective at all times, Maintain and enhance PM consistency on a component, system and Site basis, Ensure that new predictive maintenance techniques are applied and integrated with the PM program, Ensure that mandated PM tasks are identified and executed, Provide a mechanism for craft feedback, Meet regulatory requirements for PM program effectiveness, and Provide PM task deferral

Preventive maintenance and the interval availability distribution of an unreliable production system

International Nuclear Information System (INIS)

Dijkhuizen, G. van; Heijden, M. van der

1999-01-01

Traditionally, the optimal preventive maintenance interval for an unreliable production system has been determined by maximizing its limiting availability. Nowadays, it is widely recognized that this performance measure does not always provide relevant information for practical purposes. This is particularly true for order-driven manufacturing systems, in which due date performance has become a more important, and even a competitive factor. Under these circumstances, the so-called interval availability distribution is often seen as a more appropriate performance measure. Surprisingly enough, the relation between preventive maintenance and interval availability has received little attention in the existing literature. In this article, a series of mathematical models and optimization techniques is presented, with which the optimal preventive maintenance interval can be determined from an interval availability point of view, rather than from a limiting availability perspective. Computational results for a class of representative test problems indicate that significant improvements of up to 30% in the guaranteed interval availability can be obtained, by increasing preventive maintenance frequencies somewhere between 10 and 70%

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

International Nuclear Information System (INIS)

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.

A PSO approach for preventive maintenance scheduling optimization

International Nuclear Information System (INIS)

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)

Presenting a model of repair and preventing maintenance of Bushehr nuclear power plants analyzing the data of similar nuclear power plants

International Nuclear Information System (INIS)

Parikhan, Hammidreza

1997-01-01

Due to the increase application of nuclear energy for producing electricity, special attention must be paid to their maintenance activities in general and preventive maintenance in particular. It has been shown that a well established preventive maintenance programme will enhance the reliability and availability of nuclear power plants. A model of preventive maintenance for Buhehr nuclear power plant which is due to be completed by 2001 is developed. The prescribed model is based on past experiences of VVER nuclear power plants around the world. The utilized data is provided by International Atomic Energy Agency (IAEA) in Vienna, Austria. The data and past experiences reveal such important information as availability, energy loss, types of failures, duration of failure, etc. A strategy for designing a database is established. These data are then analyzed by statistical methods such as Pareto analysis, t-test, K-S test, analysis of variance, etc. The results of our analysis reveal important information in regard to establishment of a well-defined preventive maintenance programme in Buhshehr nuclear power plant. The results show that certain equipment such turbo-generator and control-rods play an important role in the maintenance of a VVER nuclear power plant. Other findings are discussed in great detail

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

Directory of Open Access Journals (Sweden)

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.

A preventive maintenance lubricant

Energy Technology Data Exchange (ETDEWEB)

Chapaykina, S A; Ol' kov, P L; Pertsev, A N; Rodzevillo, I T; Rogacheva, O I; Zinov' yev, A P

1980-02-15

A method is disclosed to lower the adherence of materials by reducing the viscosity of a preventive maintenance lubricant against adhesion of moist, freeflowing materials, containing extract of selective cleaning of oil fractions and asphalt. Gas oil of catalytic cracking is added having a boiling point of 190-300 degrees, with the following ratio of components (%): selective cleaning extract, 43-50; asphalt, 14-16; and gas oil of catalytic cracking, the remainder, Treating a surface with the proposed lubricant lowers the specific resistance to shift of rock compared with the prototype (g/cm/sup 2/): sand (moisture content, 18%) from 3.82 to 1.55; and clay (moisture content 16%), from 5.41 to 3.51.

Reliability theory with applications to preventive maintenance

CERN Document Server

Gertsbakh, Ilya

2000-01-01

The material in this book was first presented as a one-semester course in Relia­ bility Theory and Preventive Maintenance for M.Sc. students of the Industrial Engineering Department of Ben Gurion University in the 1997/98 and 1998/99 academic years. Engineering students are mainly interested in the applied part of this theory. The value of preventive maintenance theory lies in the possibility of its imple­ mentation, which crucially depends on how we handle statistical reliability data. The very nature of the object of reliability theory - system lifetime - makes it extremely difficult to collect large amounts of data. The data available are usu­ ally incomplete, e.g. heavily censored. Thus, the desire to make the course material more applicable led me to include in the course topics such as mod­ eling system lifetime distributions (Chaps. 1,2) and the maximum likelihood techniques for lifetime data processing (Chap. 3). A course in the theory of statistics is aprerequisite for these lectures. Stan­ dard...

Control-limit preventive maintenance policies for components subject to imperfect preventive maintenance and variable operational conditions

International Nuclear Information System (INIS)

You Mingyi; Li Hongguang; Meng Guang

2011-01-01

This paper develops two component-level control-limit preventive maintenance (PM) policies for systems subject to the joint effect of partial recovery PM acts (imperfect PM acts) and variable operational conditions, and investigates the properties of the proposed policies. The extended proportional hazards model (EPHM) is used to model the system failure likelihood influenced by both factors. Several numerical experiments are conducted for policy property analysis, using real lifetime and operational condition data and typical characterization of imperfect PM acts and maintenance durations. The experimental results demonstrate the necessity of considering both factors when they do exist, characterize the joint effect of the two factors on the performance of an optimized PM policy, and explore the influence of the loading sequence of time-varying operational conditions on the performance of an optimized PM policy. The proposed policies extend the applicability of PM optimization techniques.

design of preventive maintenance scheduling model for ...

African Journals Online (AJOL)

connected in parallel, Rj(ti) is the reliability of the jth unit at ith time interval, n is the to- tal number of systems (components or units) connected in parallel. Equations (3) and (4) enable us to deter- mine the reliability of all components, units or sub-systems in an industry. 5. System Reliability with Preventive. Maintenance. Fig.

Preventive maintenance for computer systems - concepts & issues ...

African Journals Online (AJOL)

Performing preventive maintenance activities for the computer is not optional. The computer is a sensitive and delicate device that needs adequate time and attention to make it work properly. In this paper, the concept and issues on how to prolong the life span of the system, that is, the way to make the system last long and ...

Multi-objective group scheduling optimization integrated with preventive maintenance

Science.gov (United States)

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.

Preventive maintenance plan of the air-conditioning duct using the ACM-sensor

International Nuclear Information System (INIS)

Fukuba, Kazushi; Ito, Takanobu; Kojima, Akiko; Tanji, Kazuhiro; Sato, Yuki

2013-01-01

Air-conditioning duct is difficult to predict the date to occur of corrosion such as affect the function. Therefore, the current conservation method is mostly corrective maintenance. Therefore, we used the test pieces of six types and ACM-sensor in order to solve the corrosion speed from corrosion environment and relationship of corrosion quantity of test pieces. In addition, was used the duct molded articles various in order to check the corrosion degree of when processed the duct. As a result, we were selected crust body constituting a duct and optimal combination of the flange by solve the corrosion speed of the test pieces various. Thus, it performs preventive disposal before to occur of corrosion such as affect the function by predicting the duct life from corrosion speed, and lead to stability and safe operating by appropriate maintenance of equipment. (author)

Development of preventive maintenance technology and advanced service equipment for operating nuclear power plants

International Nuclear Information System (INIS)

Abe, Kazuhiro; Sumikawa, Masaharu; Hirakawa, Hiromasa; Arakawa, Tadao; Hasegawa, Kunio; Kato, Kanji.

1990-01-01

Hitachi Ltd. as a manufacturer of nuclear power plants has carried out the consistent general preventive maintenance activities from the planning of the plants and the design of maintainability in the construction phase to the planning and working of preventive maintenance in the operation and maintenance phase, and exerted efforts to heighten the capacity ratio and reliability of the plants. For the purpose, the steady activities of reliability improvement have been carried out throughout the whole company, and the rationalization of the planning and management of the preventive maintenance with a computer and the development of the robots to which Al is applied have been promoted. As the technology of upgrading the facilities, boron racks, the control rods having long life and so on were developed, and their practical use is advanced. Moreover for the future, the development of the diagnostic technology on material deterioration using superconductive quantum interference devices (SQUID) is in progress. The preventive maintenance activities in Hitachi Ltd., the technical development for the purpose and the upgrading of the plant facilities are reported. (K.I.)

Preventive maintenance program of motorized operated valves (MOV) at Cernavoda NPP

International Nuclear Information System (INIS)

Groza, M.; Moldoveanu, Edy

2001-01-01

This is a Power Point presentation. The following objectives are addressed: A. Determine the target of MOV program; B. Define the strategy for MOV; C. Establish the MOV program execution phases; D. Identification of key parameters; E. Examples. The target of MOV program is to improve the safety by ensuring the adequacy of safety valves and the reliability of safety equipment and, subsequently, to ensure the economic operation of the plant. Consequences of MV malfunction are indicated. The strategy for MOV program development is both general, namely, to define the minimal requirements of preventive /corrective maintenance activities for all MOV's according to design/ manufacture specification and particular, namely to identify MV's specific problems and the need for increasing/decreasing the preventing maintenance tasks or frequency established in 'general' MOV program. Strategy for MOV program development implies: - Establish MOV program applicability; - Develop diagnostic strategy (define key parameters ); - Perform program for engineering review; - Establish program for preventive maintenance; - Revise procedures for operating and maintenance tests; - Dynamic evaluation of MOV. The program execution phases are listed as follows: 1. Perform risk assessment of the MOV's to determine criticality level (program applicability); 2. Collect data to fill in MOV Application Data Sheet; 3. Perform engineering review to determine functional parameters acceptable range and determine key parameters; 4. Analysis for maintenance tasks / frequencies selection and determination of implementing actions (engineer review); 5. Prepare work packages for availability confirmation; 6. Schedule and plan corrective actions or provide input to other programs; 7. Schedule and plan implementing actions in preparation for program field execution; 8. Program field implementation; 9. Program monitoring, evaluation and optimization. The criteria defining the key operational and maintenance

Probabilistic sensitivity analysis of optimised preventive maintenance strategies for deteriorating infrastructure assets

International Nuclear Information System (INIS)

Daneshkhah, A.; Stocks, N.G.; Jeffrey, P.

2017-01-01

Efficient life-cycle management of civil infrastructure systems under continuous deterioration can be improved by studying the sensitivity of optimised preventive maintenance decisions with respect to changes in model parameters. Sensitivity analysis in maintenance optimisation problems is important because if the calculation of the cost of preventive maintenance strategies is not sufficiently robust, the use of the maintenance model can generate optimised maintenances strategies that are not cost-effective. Probabilistic sensitivity analysis methods (particularly variance based ones), only partially respond to this issue and their use is limited to evaluating the extent to which uncertainty in each input contributes to the overall output's variance. These methods do not take account of the decision-making problem in a straightforward manner. To address this issue, we use the concept of the Expected Value of Perfect Information (EVPI) to perform decision-informed sensitivity analysis: to identify the key parameters of the problem and quantify the value of learning about certain aspects of the life-cycle management of civil infrastructure system. This approach allows us to quantify the benefits of the maintenance strategies in terms of expected costs and in the light of accumulated information about the model parameters and aspects of the system, such as the ageing process. We use a Gamma process model to represent the uncertainty associated with asset deterioration, illustrating the use of EVPI to perform sensitivity analysis on the optimisation problem for age-based and condition-based preventive maintenance strategies. The evaluation of EVPI indices is computationally demanding and Markov Chain Monte Carlo techniques would not be helpful. To overcome this computational difficulty, we approximate the EVPI indices using Gaussian process emulators. The implications of the worked numerical examples discussed in the context of analytical efficiency and organisational

A reliability-based preventive maintenance methodology for the projection spot welding machine

Directory of Open Access Journals (Sweden)

Fayzimatov Ulugbek

2018-06-01

Full Text Available An effective operations of a projection spot welding (PSW machine is closely related to the effec-tiveness of the maintenance. Timely maintenance can prevent failures and improve reliability and maintainability of the machine. Therefore, establishing the maintenance frequency for the welding machine is one of the most important tasks for plant engineers. In this regard, reliability analysis of the welding machine can be used to establish preventive maintenance intervals (PMI and to identify the critical parts of the system. In this reliability and maintainability study, analysis of the PSW machine was carried out. The failure and repair data for analysis were obtained from automobile manufacturing company located in Uzbekistan. The machine was divided into three main sub-systems: electrical, pneumatic and hydraulic. Different distributions functions for all sub-systems was tested and their parameters tabulated. Based on estimated parameters of the analyzed distribu-tions, PMI for the PSW machines sub-systems at different reliability levels was calculated. Finally, preventive measures for enhancing the reliability of the PSW machine sub-systems are suggested.

Preventive Maintenance Interval Prediction: a Spare Parts Inventory Cost and Lost Earning Based Model

Directory of Open Access Journals (Sweden)

O. A. Adebimpe

2015-06-01

Full Text Available In this paper, some preventive maintenance parameters in manufacturing firms were identified and used to develop cost based functions in terms of machine preventive maintenance. The proposed cost based model considers system’s reliability, cost of keeping spare parts inventory and lost earnings in deriving optimal maintenance interval. A case of a manufacturing firm in Nigeria was observed and the data was used to evaluate the model.

A preventive maintenance model for leased equipment subject to internal degradation and external shock damage

International Nuclear Information System (INIS)

Zhou, Xiaojun; Wu, Changjie; Li, Yanting; Xi, Lifeng

2016-01-01

A periodic preventive maintenance modeling method is proposed for leased equipment with continuous internal degradation and stochastic external shock damage considered simultaneously, which can facilitate the equipment lessor to optimize the maintenance schedule for the same kind of equipment rented by different lessees. A novel interactive mechanism between the continuous internal degradation and the stochastic external shock damage is established on the hazard rate of the equipment with integrating the imperfect effect of maintenance. Two improvement factors are defined for the modeling of imperfect maintenance. The number of failures resulting from internal degradation and from external shocks are both mathematically deduced based on this interactive mechanism. The optimal preventive maintenance scheme is obtained by minimizing the cumulative maintenance cost throughout the lease period. Numerical example shows that the proposed preventive maintenance model not only can reflect the reliability status of the equipment but also can clearly distinguish between the impact from internal degradation and that from external shocks. - Highlights: • We propose an imperfect periodic preventive maintenance model for leased equipment. • It can distinguish between the impact from internal degradation and that from external shocks. • An internal–external interactive mechanism is proposed. • Two improvement factors are introduced into the modeling of imperfect maintenance. • The model is helpful for the PM scheduling of the same equipment rented by different lessees.

PERANCANGAN PENJADWALAN PREVENTIVE MAINTENANCE PADA PT. ARTHA PRIMA SUKSES MAKMUR

Directory of Open Access Journals (Sweden)

Yugowati Praharsi

2015-06-01

Full Text Available PT. Artha Prima Sukses Makmur memiliki lima mesin dalam menjalankan kegiatan produksi sol sepatu yang berlangsung 24 jam setiap hari, sehingga kegiatan perawatan dan pemeliharaan perlu dilakukan dengan baik dan dijadwalkan agar tidak mengganggu kegiatan produksi yang sedang berlangsung. Kerusakan mesin saat ini masih terhitung tinggi dan memerlukan waktu perbaikan yang cukup lama. Perancangan penjadwalan maintenancediperlukan untuk mengurangi downtime pada mesin, sehingga tidak menghambat dan mengganggu jadwal produksi. Penjadwalan yang diusulkan adalah preventive maintenance dengan metode age replacement. Berdasarkan prinsip Pareto terdapat dua mesin kritis dari lima mesin yang ada.Hasil perhitungan dari data kerusakan mesin sebelumnya diketahui, jika dilakukan preventive maintenance downtime akan berkurang sebanyak 2.85%, dan terjadi penghematan sebesar 38%.

PERANCANGAN PENJADWALAN PREVENTIVE MAINTENANCE PADA PT. ARTHA PRIMA SUKSES MAKMUR

Directory of Open Access Journals (Sweden)

Yugowati Praharsi

2015-06-01

Full Text Available PT. Artha Prima Sukses Makmur memiliki lima mesin dalam menjalankan kegiatan produksi sol sepatu yang berlangsung 24 jam setiap hari, sehingga kegiatan perawatan dan pemeliharaan perlu dilakukan dengan baik dan dijadwalkan agar tidak mengganggu kegiatan produksi yang sedang berlangsung. Kerusakan mesin saat ini masih terhitung tinggi dan memerlukan waktu perbaikan yang cukup lama. Perancangan penjadwalan  maintenancediperlukan untuk mengurangi downtime pada mesin, sehingga tidak menghambat dan mengganggu jadwal produksi. Penjadwalan yang diusulkan adalah preventive maintenance dengan metode age replacement. Berdasarkan prinsip Pareto terdapat dua mesin kritis dari lima mesin yang ada.Hasil perhitungan dari data kerusakan mesin sebelumnya diketahui, jika dilakukan preventive maintenance downtime akan berkurang sebanyak 2.85%, dan terjadi penghematan sebesar 38%.

Fleet equipment performance measurement preventive maintenance model : final report.

Science.gov (United States)

2014-04-01

The concept of preventive maintenance is very important in the effective management and deployment of : vehicle fleets. The Texas Department of Transportation (TxDOT) operates a large fleet of on-road and offroad : equipment. Newer engines and vehicl...

A preventive maintenance policy based on dependent two-stage deterioration and external shocks

International Nuclear Information System (INIS)

Yang, Li; Ma, Xiaobing; Peng, Rui; Zhai, Qingqing; Zhao, Yu

2017-01-01

This paper proposes a preventive maintenance policy for a single-unit system whose failure has two competing and dependent causes, i.e., internal deterioration and sudden shocks. The internal failure process is divided into two stages, i.e. normal and defective. Shocks arrive according to a non-homogeneous Poisson process (NHPP), leading to the failure of the system immediately. The occurrence rate of a shock is affected by the state of the system. Both an age-based replacement and finite number of periodic inspections are schemed simultaneously to deal with the competing failures. The objective of this study is to determine the optimal preventive replacement interval, inspection interval and number of inspections such that the expected cost per unit time is minimized. A case study on oil pipeline maintenance is presented to illustrate the maintenance policy. - Highlights: • A maintenance model based on two-stage deterioration and sudden shocks is developed. • The impact of internal system state on external shock process is studied. • A new preventive maintenance strategy combining age-based replacements and periodic inspections is proposed. • Postponed replacement of a defective system is provided by restricting the number of inspections.

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

International Nuclear Information System (INIS)

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

Reusable rocket engine preventive maintenance scheduling using genetic algorithm

International Nuclear Information System (INIS)

Chen, Tao; Li, Jiawen; Jin, Ping; Cai, Guobiao

2013-01-01

This paper deals with the preventive maintenance (PM) scheduling problem of reusable rocket engine (RRE), which is different from the ordinary repairable systems, by genetic algorithm. Three types of PM activities for RRE are considered and modeled by introducing the concept of effective age. The impacts of PM on all subsystems' aging processes are evaluated based on improvement factor model. Then the reliability of engine is formulated by considering the accumulated time effect. After that, optimization model subjected to reliability constraint is developed for RRE PM scheduling at fixed interval. The optimal PM combination is obtained by minimizing the total cost in the whole life cycle for a supposed engine. Numerical investigations indicate that the subsystem's intrinsic reliability characteristic and the improvement factor of maintain operations are the most important parameters in RRE's PM scheduling management

The cost function for the preventive - maintenance replacement problem

OpenAIRE

Vilaplana, Jose Perez

1994-01-01

Let a discounted continuous review preventive-maintenance replacement model be such that its total discounted cost is given by means of two functional equations. We assume that downtime is caused by equipment breakdowns, and the length of a given downtime is the time necessary to repair the equipment and set it back in operation. The periodic preventive replacement policy is to replace the equipment by a new identical equipment when service age X is reached, or when the equipment ...

The economy of preventive maintenance of concrete bridges : final report.

Science.gov (United States)

2016-03-01

The most economical approach to maintain existing concrete bridges is by adopting an active preventive maintenance : approach. An in-depth investigation of the combined deterioration effects of various deterioration mechanisms is needed : to establis...

Integrating the sequence dependent setup time open shop problem and preventive maintenance policies

Directory of Open Access Journals (Sweden)

K. Naboureh

2016-09-01

Full Text Available In most industrial environments, it is usually considered that machines are accessible throughout the planning horizon, but in real situation, machines may be unavailable due to a scheduled preventive maintenance where the periods of unavailability are known in advance. The main idea of this paper is to consider different preventive maintenance policies on machines regarding open shop scheduling problem (OSSP with sequence dependent setup times (SDST using immune algorithm. The preventive maintenance (PM policies are planned for maximizing availability of machines or keeping minimum level of reliability through the production horizon. The objective function of the paper is to minimize makespan. In total, the proposed algorithm extensively is compared with six adaptations of existing heuristic and meta-heuristic methods for the problem through data sets from benchmarks based on Taillard’s instances with some adjustments. The results show that the proposed algorithm outperforms other algorithms for this problem.

RoVi: Continuous transport infrastructure monitoring framework for preventive maintenance

NARCIS (Netherlands)

Seraj, Fatjon; Meratnia, Nirvana; Havinga, Paul J.M.

2017-01-01

Ground transport infrastructures require in-situ monitoring to evaluate their condition and deterioration and to design appropriate preventive maintenance strategies. Current monitoring practices provide accurate and detailed spatial measurements but often lack the required temporal resolution. This

University of Tennessee - Industry collaborative research and development in preventive maintenance technology

International Nuclear Information System (INIS)

Upadhyaya, B.R.

1992-01-01

The Preventive Maintenance Engineering Laboratory (PMEL) was inaugurated at the University of Tennessee Nuclear Engineering Department in September 1989. The startup funding was provided by Gilbert/Commonwealth, Inc. The purpose of PMEL is to identify maintenance-related problems in the power and process industries and to find their solutions through the development and application of emerging technologies. These include advanced digital signal processing, applied artificial intelligence (AI), artificial neural networks, and reliability based methods. The Laboratory activities are being expanded by the formation of an industrial consortium within the Measurement and Control Engineering Center at the University of Tennessee. Several research and development projects in preventive maintenance are being carried out. These include condition monitoring of air operated valves, automated diagnostics of motor operated valves, instrument calibration, verification, and estimation of expected residual life of electric motors using applied AI technology and reliability-based methods. The new methodology will be applied to other industrial subsystems. A long-term research and development project is being sponsored by the T.V.A. Nuclear Maintenance Department. The overall objective of the research program is to develop and apply advanced artificial intelligence and information processing methods to the problems of plant performance monitoring and preventive maintenance. The program includes the development of a workstation/PC-based, networking of plant information for easy access to operational and management personnel, implementation of a sensor verification system, monitoring of feedwater flow venturi fouling and heat rate balance, and integration of signal validation, command validation, and fault-tolerant control strategies

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

International Nuclear Information System (INIS)

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)

Preventive maintenance scheduling by variable dimension evolutionary algorithms

International Nuclear Information System (INIS)

Limbourg, Philipp; Kochs, Hans-Dieter

2006-01-01

Black box optimization strategies have been proven to be useful tools for solving complex maintenance optimization problems. There has been a considerable amount of research on the right choice of optimization strategies for finding optimal preventive maintenance schedules. Much less attention is turned to the representation of the schedule to the algorithm. Either the search space is represented as a binary string leading to highly complex combinatorial problem or maintenance operations are defined by regular intervals which may restrict the search space to suboptimal solutions. An adequate representation however is vitally important for result quality. This work presents several nonstandard input representations and compares them to the standard binary representation. An evolutionary algorithm with extensions to handle variable length genomes is used for the comparison. The results demonstrate that two new representations perform better than the binary representation scheme. A second analysis shows that the performance may be even more increased using modified genetic operators. Thus, the choice of alternative representations leads to better results in the same amount of time and without any loss of accuracy

Preventative and predictive maintenance as a function of spare part management

International Nuclear Information System (INIS)

LaRose, R.; Sloski, P.

2006-01-01

Preventive and predictive maintenance has many aspects, such as vibration monitoring, lubricating oil analysis, thermography etc. This presentation focuses on the material and design application of sealing devices. (author)

Using the intervention mapping protocol to develop a maintenance programme for the SLIMMER diabetes prevention intervention.

Science.gov (United States)

Elsman, Ellen B M; Leerlooijer, Joanne N; Ter Beek, Josien; Duijzer, Geerke; Jansen, Sophia C; Hiddink, Gerrit J; Feskens, Edith J M; Haveman-Nies, Annemien

2014-10-27

Although lifestyle interventions have shown to be effective in reducing the risk for type 2 diabetes mellitus, maintenance of achieved results is difficult, as participants often experience relapse after the intervention has ended. This paper describes the systematic development of a maintenance programme for the extensive SLIMMER intervention, an existing diabetes prevention intervention for high-risk individuals, implemented in a real-life setting in the Netherlands. The maintenance programme was developed using the Intervention Mapping protocol. Programme development was informed by a literature study supplemented by various focus group discussions and feedback from implementers of the extensive SLIMMER intervention. The maintenance programme was designed to sustain a healthy diet and physical activity pattern by targeting knowledge, attitudes, subjective norms and perceived behavioural control of the SLIMMER participants. Practical applications were clustered into nine programme components, including sports clinics at local sports clubs, a concluding meeting with the physiotherapist and dietician, and a return session with the physiotherapist, dietician and physical activity group. Manuals were developed for the implementers and included a detailed time table and step-by-step instructions on how to implement the maintenance programme. The Intervention Mapping protocol provided a useful framework to systematically plan a maintenance programme for the extensive SLIMMER intervention. The study showed that planning a maintenance programme can build on existing implementation structures of the extensive programme. Future research is needed to determine to what extent the maintenance programme contributes to sustained effects in participants of lifestyle interventions.

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

International Nuclear Information System (INIS)

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.

Opportunities and supporting activities to promote preventive maintenance of NPPs in Japan

International Nuclear Information System (INIS)

Sanada, A.; Shinkawa, T.; Sakurada, M.

1998-01-01

With increase of the number of NPPs and operation history, enhancement of the safety regulation is becoming important for such long-operated NPPs. Centering on the comprehensive preventive maintenance, periodic safety reviews by utilities and its review and evaluation by MITI are in progress. The first reviews have not revealed essential and critical indications to be newly implemented. This means that the most of activities to secure reliability and safety have been done steadily. The present paper addresses the mechanism of on-going preventive maintenance and its essential elements: opportunities to identify issues and problems, and supporting activities to promote decision-makings on feedback, upgrading and modernization of NPPs. (author)

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

International Nuclear Information System (INIS)

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.

Strategy and Management Guideline on Preventive School Maintenance in Eritrea

DEFF Research Database (Denmark)

Vagnby, Bo Hellisen

An action-oriented and practical guideline for the planning, organisation and management of preventive school maintenance in Eritrea. The manual is the result of a participatory planning process which has involved actors at the school and community level, district levels and the national policy...

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

Directory of Open Access Journals (Sweden)

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.

Preventive maintenance basis: Volume 1 -- Air-operated valves. Final report

International Nuclear Information System (INIS)

Worledge, D.; Hinchcliffe, G.

1997-07-01

US nuclear plants are implementing preventive maintenance (PM) tasks with little documented basis beyond fundamental vendor information to support the tasks or their intervals. The Preventive Maintenance Basis project provides utilities with the technical basis for PM tasks and task intervals associated with 40 specific components such as valves, electric motors, pumps, and HVAC equipment. This report provides an overview of the PM Basis project and describes use of the PM Basis database. This document provides a program of PM tasks suitable for application to Air Operated Valves (AOV's) in nuclear power plants. The PM tasks that are recommended provide a cost-effective way to intercept the causes and mechanisms that lead to degradation and failure. They can be used, in conjunction with material from other sources, to develop a complete PM program or to improve an existing program. Users of this information will be utility managers, supervisors, craft technicians, and training instructors responsible for developing, optimizing, or fine-tuning PM programs

Development of a Preventive Maintenance Program for Tooling Used in Powder Slush Molding

Energy Technology Data Exchange (ETDEWEB)

Lara-Curzio, Edgar [ORNL; Rios, Orlando [ORNL; Marquez Rossy, Andres E [ORNL

2016-07-19

ORNL collaborated with Faurecia Interior Systems to investigate the feasibility of developing a thermomagnetic preventive maintenance program for nickel tooling used in powder slush molding. It was found that thermal treatments at temperatures greater than 500°C can anneal strain hardening in nickel tooling and a range of temperatures and times for effective thermal annealing were identified. It was also observed that magnetic fields applied during thermal annealing do not alter the kinetics of strain hardening annealing. The results obtained in this investigation provide a foundation for establishing a preventive maintenance program for nickel tooling.

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

Directory of Open Access Journals (Sweden)

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.

Aging management and preventive maintenance for nuclear power plants

International Nuclear Information System (INIS)

Bessho, Toichi; Sagawa, Wataru; Oyamada, Osamu; Uchida, Shunsuke

1995-01-01

It is expected that nuclear power generation will bear main electric power supply for long term. For this purpose, by applying proper preventive maintenance to the nuclear power plants in operation, the maintenance of high reliability and the rate of plant operation is extremely important. Especially it has been strongly demanded to execute efficiently the periodic inspection which is carried out every year to shorten its period and increase the rate of operation, and to maintain the reliability by the proper maintenance for the aged plants with long operation years. As to efficient and short periodic inspection, the preparation is advanced by the guidance of electric power companies aiming at realizing it in nearest fiscal year, and further, effort is exerted for the development of technology in long term to optimize periodic inspection. For securing the reliability of aged plants, it is important to do proper inspection and diagnosis and to take the countermeasures by repair and replacement, based on the grasp of secular change mechanism and the evaluation of life of machinery, equipment and materials. In particular, effort is exerted for the development of maintenance technology for reactor pressure vessels and in-core equipment which are hard to access. The confirmation of the function of remote operation equipment and the establishment of execution condition are carried out by uisng the full scale mock-up of BWR plant. The problems in maintenance service and the activities and results of reliability improvement are reported. (K.I.)

Preventive maintenance at the Forsmark Nuclear Power Plant

International Nuclear Information System (INIS)

Danielsson, H.

1985-01-01

The maintenance system at the Forsmark Nuclear Power Plant began in 1975, and was drawn up in co-operation with other power stations within the control of the Swedish State Power Board. Preventive maintenance (PM) is part of the system and has been in operation since 1978. Great efforts have been made to build up the system and to gather input data. Since 1981, the system has been in continuous use; follow-ups and system and quality improvements in database contents have been carried out. Great effort has also been devoted to maintaining a high quality of database contents and to the interplay between the different PM measures. We believe that PM plays an important role in the safety and economic operation of the power station and that it is essential that interest in PM should exist at all levels of the power company. (author)

Where does “whichever occurs first” hold for preventive maintenance modelings?

International Nuclear Information System (INIS)

Zhao, Xufeng; Liu, Hu-Chen; Nakagawa, Toshio

2015-01-01

The purpose of this paper is to observe where the classical assumption “whichever occurs first” holds for preventive maintenance (PM) modelings. We firstly take up a bivariate maintenance policy where “whichever occurs first” and the newly proposed “whichever occurs last” are respectively used. Modification of PM performance is introduced into modelings to avoid interruptions of job executions, that is, PMs are done only at the end of working cycles. From the points of performability and maintenance cost, we secondly compare the optimized “first” and “last” policies in detail and find two critical points of comparisons analytically. Further, by comparing the “first” and “last” policies with the standard maintenance, modified PM costs are obtained to observe whether it is easy to save PM cost for “whichever occurs first”. For a trivariate maintenance policy, we thirdly propose an entirely new assumption “whichever occurs middle” and give another one model that considers both assumptions of “first” and “last”. We analyze maintenance probabilities for each model and then obtain directly their expected maintenance cost rates for further studies. - Highlights: • A bivariate maintenance policy based on “whichever occurs first” is improved. • Two comparisons of “whichever occurs first and last” are made. • Modified maintenance costs are obtained to observe which policy could save more costs. • New assumption “whichever occurs middle” for the trivariate maintenances is proposed. • One policy is modeled by considering both assumptions of “first” and “last”

An optimal dynamic interval preventive maintenance scheduling for series systems

International Nuclear Information System (INIS)

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

The Preventive Signaling Maintenance Crew Scheduling Problem for European Railway Traffic Management system (ERTMS)

DEFF Research Database (Denmark)

M. Pour, Shahrzad; Stidsen, Thomas Jacob Riis; Rasmussen, Kourosh Marjani

, the western part of Denmark. This case is particularly interesting, since the entire railway signalling system is currently being upgraded to the new European Railway Traffic Management System (ERTMS) standard. The new signals need continuous maintenance and in this article we plan the distribution of crew......A railway system is a large and complex infrastructure, which requires continuous maintenance in order to function correctly. Proper maintenance is critical but can also be costly. In this paper we consider the practical case of planning the preventive maintenance of railway signals in Jutland...

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

International Nuclear Information System (INIS)

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)

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

Directory of Open Access Journals (Sweden)

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.

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

Directory of Open Access Journals (Sweden)

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.

Preventive maintenance - An important element in the `risk management` philosophy

Energy Technology Data Exchange (ETDEWEB)

Gullev, Lars [VEKS (Denmark)

1996-11-01

The contents of the paper is a presentation of the company VEKS with particular focus on the connection between preventive maintenance and the `Risk Management` philosophy. Implementation of Risk Management was preferred instead of an ISO-9000 certification of the company. The experience is that the responsibility in the organisation has been increased. (au)

An approach to integrating surveillance and maintenance tasks to prevent the dominant failure causes of critical components

International Nuclear Information System (INIS)

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

1995-01-01

Surveillance requirements and maintenance activities in a nuclear power plant aim to preserve components' inherent reliability. Up to now, predictive and preventive maintenance mainly concerned plant staff, but the US Nuclear Regulatory Commission Maintenance Rule released in July 1991 will have significant impact on how nuclear power plants perform and document this maintenance. Reliability Centered Maintenance (RCM) is a systematic methodology to establish maintenance tasks for critical components in plant with a high degree of compliance with the goals of the Rule. RCM pursues the identification of applicable and efficient tasks to prevent these components from developing their dominant failure causes, and, in turn, towards achieving proper levels of components availability with low cost. In this paper, we present an approach for identifying the most suitable set of tasks to achieve this goal, which involves the integration of maintenance activities and surveillance requirements for each critical component based on the unavailability and cost associated with each individual task which is performed on it

Stress-reducing preventive maintenance model for a unit under stressful environment

International Nuclear Information System (INIS)

Park, J.H.; Chang, Woojin; Lie, C.H.

2012-01-01

We develop a preventive maintenance (PM) model for a unit operated under stressful environment. The PM model in this paper consists of a failure rate model and two cost models to determine the optimal PM scheduling which minimizes a cost rate. The assumption for the proposed model is that stressful environment accelerates the failure of the unit and periodic maintenances reduce stress from outside. The failure rate model handles the maintenance effect of PM using improvement and stress factors. The cost models are categorized into two failure recognition cases: immediate failure recognition and periodic failure detection. The optimal PM scheduling is obtained by considering the trade-off between the related cost and the lifetime of a unit in our model setting. The practical usage of our proposed model is tested through a numerical example.

A comprehensive approach to RCM-based preventive maintenance program development

International Nuclear Information System (INIS)

Hall, B.E.; Davis, T.; Pennington, A.J.

1988-01-01

In late 1986, Public Service Electric and Gas Company (PSE ampersand G) concluded that to support its vision and strategic planning it would be necessary to develop a consistent approach to maintenance for all nuclear units at the artificial island. General Physics Corporation was selected to lead a consultant team to support full-scale development of a preventive maintenance (PM) program for Salem and Hope Creek generating stations based on a reliability-centered maintenance (RCM) approach. RCM was selected because it represents a systematic approach to developing a PM program that provides a logical, consistent, and traceable methodology and produces a well-documented engineering basis for the program. Early in 1987, primary objectives for the PM program were defined. The Phase I tasks addressed key programmatic areas such as maintenance philosophy, procedures, condition monitoring, performance trending, equipment failure data base, ogranization, PM program effectiveness evaluation, RCM process, reliability/availability modeling, information management, training, spare parts, software/hardware, and commitments. Phase I of the PM program development project was completed in January 1988. Highlights of the Phase I work and the PM program manual are described

An evaluation of the Browns Ferry Nuclear Plant preventive maintenance program based on reliability centered maintenance analysis

International Nuclear Information System (INIS)

McCullough, C.L.; McCullough, C.A.

1989-01-01

Reliability centered maintenance (RCM) techniques were used to support a preventative maintenance (PM) upgrade program (PMUP) performed at TVA Browns Ferry Nuclear Plant (BFNP). The purpose of the RCM analysis was to identify critical equipment based on risk and economic importance and to evaluate the PM activities applicable to that equipment. The analysis may be conveniently divided into three steps, which will be outlined in the Approach section of this paper. The net benefit of the RCM approach was a prioritization of the focus of the PM upgrade program so that plant components receive attention proportional to their importance, and assurance that PM activities properly address the most likely component failure causes

Condition-based maintenance at both scheduled and unscheduled opportunities

NARCIS (Netherlands)

Kalosi, S.; Kapodistria, S.; Resing, J.A.C.

2016-01-01

Motivated by original equipment manufacturer (OEM) service and maintenance practices we consider a single component subject to replacements at failure instances and two types of preventive maintenance opportunities: scheduled, which occur due to periodic system reviews of the equipment, and

Preventive maintenance basis: Volume 24 -- Battery -- flooded lead-acid (lead-calcium, lead antimony, plante). Final report

International Nuclear Information System (INIS)

Worledge, D.; Hinchcliffe, G.

1997-12-01

US nuclear power plants are implementing preventive maintenance (PM) tasks with little documented basis beyond fundamental vendor information to support the tasks or their intervals. The Preventive Maintenance Basis project provides utilities with the technical basis for PM tasks and task intervals associated with 40 specific components such as valves, electric motors, pumps, and HVAC equipment. This document provides a program of preventive maintenance tasks suitable for application to flooded lead-acid batteries. The PM tasks that are recommended provide a cost-effective way to intercept the causes and mechanisms that lead to degradation and failure. They can be used in conjunction with material from other sources, to develop a complete PM program or to improve an existing program. This document provides a program of preventive maintenance (PM) tasks suitable for application to flooded lead-acid batteries. The PM tasks that are recommended provide a cost-effective way to intercept the causes and mechanisms that lead to degradation and failure. They can be used, in conjunction with material from other sources, to develop a complete PM program or to improve an existing program. Users of this information will be utility managers, supervisors, system engineers, craft technicians, and training instructors responsible for developing, optimizing, or fine-tuning PM programs

Preventing Type 2 Diabetes

Science.gov (United States)

... Sexual, & Bladder Problems Clinical Trials Preventing Type 2 Diabetes Perhaps you have learned that you have a ... I lower my chances of developing type 2 diabetes? Research such as the Diabetes Prevention Program shows ...

Preventive maintenance basis: Volume 21 -- HVAC, air handling equipment. Final report

International Nuclear Information System (INIS)

Worledge, D.; Hinchcliffe, G.

1997-12-01

US nuclear plants are implementing preventive maintenance (PM) tasks with little documented basis beyond fundamental vendor information to support the tasks or their intervals. The Preventive Maintenance Basis project provides utilities with the technical basis for PM tasks and task intervals associated with 40 specific components such as valves, electric motors, pumps, and HVAC equipment. This report provides an overview of the PM Basis project and describes use of the PM Basis database. Volume 21 of the report provides a program of PM tasks suitable for application to HVAC-Air Handling Equipment. The PM tasks that are recommended provide a cost-effective way to intercept the causes and mechanisms that lead to degradation and failure. They can be used, in conjunction with material from other sources, to develop a complete PM program or to improve an existing program. Users of this information will be utility managers, supervisors, craft technicians, and training instructors responsible for developing, optimizing, or fine-tuning PM programs

Preventive maintenance basis: Volume 15 -- Rotary screw air compressors. Final report

International Nuclear Information System (INIS)

Worledge, D.; Hinchcliffe, G.

1997-07-01

US nuclear plants are implementing preventive maintenance (PM) tasks with little documented basis beyond fundamental vendor information to support the tasks or their intervals. The Preventive Maintenance Basis project provides utilities with the technical basis for PM tasks and task intervals associated with 40 specific components such as valves, electric motors, pumps, and HVAC equipment. This report provides an overview of the PM Basis project and describes use of the PM Basis database. Volume 15 of the report provides a program of PM tasks suitable for application to rotary screw air compressors in nuclear power plants. The PM tasks that are recommended provide a cost-effective way to intercept the causes and mechanisms that lead to degradation and failure. They can be used, in conjunction with material from other sources, to develop a complete PM program or to improve an existing program. Users of this information will be utility managers, supervisors, craft technicians, and training instructors responsible for developing, optimizing, or fine-tuning PM programs

Modeling of preventive maintenance changes influence upon flight safety indexes

Directory of Open Access Journals (Sweden)

А.В. Гончаренко

2004-03-01

Full Text Available  It is considered a simplified model of connection between the catastrophic events flow frequency and both preventive maintenance changes periodicity and diagnosis depth of aviation equipment. It is deduced specific formulas for computing the changes and diagnostics parameters influence upon the values of both the catastrophic events flow frequency and technical-economical control factor criterion of flight safety levels.

PWSCC Preventive Maintenance Activities for Alloy 600 in Japanese PWR Plants

International Nuclear Information System (INIS)

Yamamoto, K.; Sugimoto, N.; Onishi, K.; Okimura, K.

2012-01-01

Because many nuclear plants have been in operation for ages, the importance of preventive maintenance technologies is getting higher. One conspicuous problem found in pressurized water reactor (PWR) plants is the primary water stress corrosion cracking (PWSCC) observed in Alloy 600 (a kind of high nickel based alloy) parts. Alloy 600 was used for butt welds between low alloy steel and stainless steel of nozzles of Reactor Vessel (RV), Steam Generator (SG), and Pressurizer (Pz). As PWSCC occurred at these parts may cause Loss of Coolant Accident (LOCA), preventive maintenance is necessary. PWSCC is considered to be caused by a mixture of three elements: high residual tensile stress on surface, material (Alloy 600) and environment. PWSCC can be prevented by improving one of the elements. MHI has been developing stress improvement methods, for example, Water Jet Peening (WJP), Shot Peening by Ultrasonic vibration (USP), and Laser Stress Improvement Process (L-SIP). According to the situation, appropriate method is applied for each part. WJP has been applied for RV nozzles of a lot of plants in Japan. However PWSCC was observed in RV nozzles during the inspection before WJP in recent years, MHI developed the Advanced INLAY system to improve the material from Alloy 600 to Alloy 690. Alloy 600 on the inner surface of the nozzles is removed and welding with Alloy 690 is performed. In addition, heat treatments for the nozzles are difficult for its structural situation, so ambient temperature temper bead welding technique for RV nozzles was developed to make the heat treatments unnecessary. This paper describes countermeasures against PWSCC and introduces the maintenance activities performed in Japan. (author)

Preventive maintenance instrumentation results in Spanish nuclear power plants

International Nuclear Information System (INIS)

Curiel, M.; Palomo, M. J.; Verdu, G.; Arnaldos, A.

2010-10-01

This paper is a recompilation of the most significance results in relation to the researching in preventive and predictive maintenance in critical nuclear instrumentation for power plant operation, which it is being developed by Logistica y Acondicionamientos Industriales and the Isirym Institute of the Polytechnic University of Valencia. Instrumentation verification and test, it is a priority of the power plants control and instrumentation department's technicians. These procedures are necessary information for the daily power plant work. It is performed according to different procedures and in different moments of the fuel cycle depending on the instrumentation critical state and the monitoring process. Normally, this study is developed taking into account the instantaneous values of the instrumentation measures and, after their conversion to physical magnitude, they are analyzed according to the power plant operation point. Moreover, redundant sensors measurements are taken into consideration to the equipment and/or power plant monitoring. This work goes forward and it is in advanced to the instrument analysis as it is, independently of the operation point, using specific signal analysis techniques for preventive and predictive maintenance, with the object to obtain not only information about possible malfunctions, but the degradation scale presented in the instrument or in the system measured. We present seven real case studies of Spanish nuclear power plants each of them shall give a significant contribution to problem resolution and power plant performance. (Author)

Preventive maintenance and load testing of fixed position cranes in support of major operations

International Nuclear Information System (INIS)

Detrick, C.K.

1980-01-01

This paper will address load testing and preventive maintenance of fixed in-place cranes in general, and maintenance and load testing of the 200 ton Polar Gantry Crane at the FFTF in particular. This paper also covers the installation of a 100-ton bridge crane in the FFTF's Reactor Service Building, as well as use of these cranes in making important lifts of FFTF equipment

EPR design for maintenance

International Nuclear Information System (INIS)

Krugmann, U.

1998-01-01

Preventive maintenance is very important in achieving high plant availability. For the European Pressurized Reactor (EPR) preventive maintenance has been carefully addressed in the design stage. This is particularly necessary because of the traditionally different maintenance strategies employed in France and Germany. This paper emphasizes the following features introduced in the ERP design to minimize the duration of the refueling outage: (1) containment accessibility during power operation; (2) overall plant layout to facilitate inspections and maintenances within the containment; and (3) safety system design for enabling preventive maintenance during power operation. (author)

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

Directory of Open Access Journals (Sweden)

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.

Penerapan Preventive Maintenance Untuk Meningkatkan Reliability Pada Boiler Feed Pump PLTU Tarahan Unit 3 & 4

OpenAIRE

Saputra, Melki

2015-01-01

Pemeliharaan dan perawatan merupakan kegiatan untuk menjamin mesin dapat bekerja sebagaimana mestinya. Pemeliharaan dan perawatan menyeluruh untuk meningkatkan produktivitas perusahaan dikenal dengan Preventive Maintenance. pemeliharaan keterlibatan operator melalui kegiatan autonomous maintenance. PT. PLN (Persero) Pembangkitan Sumatera Bagian Selatan Sektor Tarahan merupakan salah satu perusahaan penghasil listrik dan semua mesinnya beroperasi selama 24 jam. Beroperasinya mesin secara c...

Condition based maintenance in the context of opportunistic maintenance

NARCIS (Netherlands)

Koochaki, Javid; Bokhorst, Jos A. C.; Wortmann, Hans; Klingenberg, Warse

2012-01-01

Condition based maintenance (CBM) uses the operating condition of a component to predict a failure event. Compared to age based replacement (ABR), CBM usually results in higher availability and lower maintenance costs, since it tries to prevent unplanned downtime and avoid unnecessary preventive

Building and integrating reliability models in a Reliability-Centered-Maintenance approach

International Nuclear Information System (INIS)

Verite, B.; Villain, B.; Venturini, V.; Hugonnard, S.; Bryla, P.

1998-03-01

Electricite de France (EDF) has recently developed its OMF-Structures method, designed to optimize preventive maintenance of passive structures such as pipes and support, based on risk. In particular, reliability performances of components need to be determined; it is a two-step process, consisting of a qualitative sort followed by a quantitative evaluation, involving two types of models. Initially, degradation models are widely used to exclude some components from the field of preventive maintenance. The reliability of the remaining components is then evaluated by means of quantitative reliability models. The results are then included in a risk indicator that is used to directly optimize preventive maintenance tasks. (author)

Preventive maintenance instrumentation results in Spanish nuclear power plants

Energy Technology Data Exchange (ETDEWEB)

Curiel, M. [Logistica y Acondicionamientos Industriales SAU, Sorolla Center, local 10, Av. de las Cortes Valencianas No. 58, 46015 Valencia (Spain); Palomo, M. J.; Verdu, G. [ISIRYM, Universidad Politecnica de Valencia, Camino de Vera s/n, Valencia (Spain); Arnaldos, A., E-mail: m.curiel@lainsa.co [TITANIA Servicios Tecnologicos SL, Sorolla Center, local 10, Av. de las Cortes Valencianas No. 58, 46015 Valencia (Spain)

2010-10-15

This paper is a recompilation of the most significance results in relation to the researching in preventive and predictive maintenance in critical nuclear instrumentation for power plant operation, which it is being developed by Logistica y Acondicionamientos Industriales and the Isirym Institute of the Polytechnic University of Valencia. Instrumentation verification and test, it is a priority of the power plants control and instrumentation department's technicians. These procedures are necessary information for the daily power plant work. It is performed according to different procedures and in different moments of the fuel cycle depending on the instrumentation critical state and the monitoring process. Normally, this study is developed taking into account the instantaneous values of the instrumentation measures and, after their conversion to physical magnitude, they are analyzed according to the power plant operation point. Moreover, redundant sensors measurements are taken into consideration to the equipment and/or power plant monitoring. This work goes forward and it is in advanced to the instrument analysis as it is, independently of the operation point, using specific signal analysis techniques for preventive and predictive maintenance, with the object to obtain not only information about possible malfunctions, but the degradation scale presented in the instrument or in the system measured. We present seven real case studies of Spanish nuclear power plants each of them shall give a significant contribution to problem resolution and power plant performance. (Author)

Coordinated preventive maintenance scheduling of GENCO and TRANSCO in restructured power systems

International Nuclear Information System (INIS)

Geetha, T.; Swarup, K. Shanti

2009-01-01

Preventive maintenance of generating units and lines, in a competitive electric energy environment is proposed. Inclusion of transmission constraints and forced outage rates, over a specified operational period is considered. For generator maintenance the objective of the ISO is to maintain adequate level of reliability throughout the operational period, for which Bender's decomposition technique is used. The objective of the GENCO is to maximize profit or to minimize loss in profit, for which transmission constrained price based unit commitment (TCPBUC), based on Lagrangian relaxation method is used. Bender's decomposition technique is used for line maintenance, with adequate level of reliability. A coordinating technique using penalty factors is incorporated to obtain convergence of the conflicting objectives. The transmission constraints are modeled using dc sensitivity factors. Detailed case studies of six-bus systems and IEEE RTS system are presented and discussed. (author)

Constrained non-linear multi-objective optimisation of preventive maintenance scheduling for offshore wind farms

Science.gov (United States)

Zhong, Shuya; Pantelous, Athanasios A.; Beer, Michael; Zhou, Jian

2018-05-01

Offshore wind farm is an emerging source of renewable energy, which has been shown to have tremendous potential in recent years. In this blooming area, a key challenge is that the preventive maintenance of offshore turbines should be scheduled reasonably to satisfy the power supply without failure. In this direction, two significant goals should be considered simultaneously as a trade-off. One is to maximise the system reliability and the other is to minimise the maintenance related cost. Thus, a non-linear multi-objective programming model is proposed including two newly defined objectives with thirteen families of constraints suitable for the preventive maintenance of offshore wind farms. In order to solve our model effectively, the nondominated sorting genetic algorithm II, especially for the multi-objective optimisation is utilised and Pareto-optimal solutions of schedules can be obtained to offer adequate support to decision-makers. Finally, an example is given to illustrate the performances of the devised model and algorithm, and explore the relationships of the two targets with the help of a contrast model.

North American nuclear maintenance best practices compared to Japanese utility maintenance practices

International Nuclear Information System (INIS)

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)

Importance of weight loss maintenance and risk prediction in the prevention of type 2 Diabetes: analysis of European Diabetes Prevention Study RCT

NARCIS (Netherlands)

Penn, L.; White, M.; Lindström, J.; Boer, den A.Th.; Blaak, E.E.; Eriksson, J.G.; Feskens, E.J.M.; Ilanne-Parikka, P.; Keinanen-Kiukaanniemi, S.M.; Walker, M.; Mathers, J.C.; Uusitupa, M.; Tuomilehto, J.

2013-01-01

Background Prevalence of type 2 diabetes (T2D) is increasing worldwide. T2D prevention by lifestyle intervention is effective. Pragmatic scalable interventions are needed, with evidence to efficiently target and monitor such interventions. We report pooled analyses of data from three European trial

Configuration management of on-line maintenance

International Nuclear Information System (INIS)

Grantom, C.R.

1996-01-01

Maintenance activities are performed on station equipment to ensure continued safe and reliable performance. Equipment reliability is thereby improved, resulting in greater confidence that the component will be capable of performing its intended (safety) function. Probabilistic Safety Assessments (PSAs) consider equipment reliability and availability to calculate Core Damage Frequency (CDF) and other risk-related values. Since maintenance activities are included in PSA analyses, the effect of equipment outages on CDF can be analyzed. Results from these types of studies can be scaled to reflect different time periods and show the time-dependent impact of planned equipment outages on CDF. These time-dependent impacts on CDF are graphically presented and referred to as ''risk profiles''. Risk profiles are being successfully used at the South Texas Project (STP) to plan preventive maintenance activities and to assess the impact of unplanned maintenance activities on plant safety. At STP, planned maintenance activities are scheduled to minimize the risk impact of unavailable equipment and to prevent the Occurrence of undesirable plant configurations. The features of the risk profiles used at STP enable the evaluation of both work scope and duration of maintenance activities to be evaluated. This is possible since the risk profile illustrates both instantaneous CDF effects and cumulative impacts to CDF

Proposal for monitoring concrete painting as a preventive maintenance tool (Abutments and pier caps).

Science.gov (United States)

2017-07-01

One of the growing number of preventive bridge maintenance activities conducted by the Kentucky Transportation Cabinet (KYTC) is washing and applying thin film protective coatings to bridge abutments and piers. Previous work conducted by Kentucky Tra...

Preventive maintenance program for a research and production reactor

International Nuclear Information System (INIS)

Rico, N.A.

1990-01-01

This program proposes a simple, rapid and efficient methodology for the task of developing a really preventive maintenance discipline. Moreover, the lower cost of its application -since it must satisfy the plant's budget-. To this purpose, an extremely economical and easily obtainable infrastructure is proposed. The following stage is referred to the commissioning system, subsequent supervision and follow-up. The experience gained from the two reactors as RA-6 (Bariloche Atomic Center) and NUR (RAE) of Argelia. Finally, the interacting characteristic of this program, since it may be rapidly adapted to different dimensions of plants, laboratories, etc., must be pointed out. (Author) [es

Cost analysis of two-dimensional warranty for products with periodic preventive maintenance

International Nuclear Information System (INIS)

Huang, Yeu-Shiang; Gau, Wei-Yo; Ho, Jyh-Wen

2015-01-01

This study uses a bivariate approach, which simultaneously considers the time and usage of a repairable product, and takes into account periodic preventive maintenance to develop a two-dimensional warranty policy for the repairable product. The proposed model is based on the bivariate Weibull process to analyze the breakdown process of a repairable product simultaneously in terms of time and usage. A repairable product may be differently utilized by various customers. We consider two types of customers: (1) customers whose product warranty is terminated because the warranty time limit has reached first; (2) customers whose product warranty is terminated because the warranty usage limit has reached first, to perform cost analyses for determining an appropriate warranty policy. However, since it is often the case that the repairable product may be equally likely purchased by the two types of customers who are equivalently important to the product manufacturer; the optimal warranty policy would thus be the equilibrium solution of the cost analyses which pay the same attention to both types of customers in order to maximize the total profit of the manufacturer. - Highlights: • We use a bivariate method to model the breakdown process. • We consider a periodic PM schedule. • We obtain an optimal two-dimensional warranty policy considering various customers. • The optimal 2D warranty is an equilibrium which satisfies both seller and buyer

Preventive maintenance basis: Volume 16 -- Power operated relief valves, solenoid actuated. Final report

International Nuclear Information System (INIS)

Worledge, D.; Hinchcliffe, G.

1997-07-01

US nuclear plants are implementing preventive maintenance (PM) tasks with little documented basis beyond fundamental vendor information to support the tasks or their intervals. The Preventive Maintenance Basis project provides utilities with the technical basis for PM tasks and task intervals associated with 40 specific components such as valves, electric motors, pumps, and HVAC equipment. This report provides an overview of the PM Basis project and describes use of the PM Basis database. This volume 16 of the report provides a program of PM tasks suitable for application to power operated relief valves (PORV's) that are solenoid actuated. The PM tasks that are recommended provide a cost-effective way to intercept the causes and mechanisms that lead to degradation and failure. They can be used, in conjunction with material from other sources, to develop a complete PM program or to improve an existing program. Users of this information will be utility managers, supervisors, craft technicians, and training instructors responsible for developing, optimizing, or fine-tuning PM programs

Predictive maintenance: A new approach in maintenance of nuclear power plants

International Nuclear Information System (INIS)

Benvenuto, F.; Ferrari, L.

2005-01-01

The maintenance services for a Nuclear Power Plant are in general aimed at reaching the following goals: - Increase component availability and consequently decrease intervention frequency; - Reduce unexpected costs from unexpected repairs; - Progressively decrease the time of each intervention; - Improve the spare parts supply efficiency; - Improve spare parts and consumable warehouse managing; - Decrease maintenance costs. Most of the currently used maintenance activities refer to run-to-failure or preventive approaches: - Run-to-failure or Corrective Maintenance means that work is only carried out when a component or system is faulty and unable to perform its critical function. Non critical components such as filters or components with spare may be maintained in this way; - Preventive or Scheduled Maintenance involves a regular pre-set schedule programme of maintenance work. Programme outlined by the manufacturer of the component in question based on the design life of the component and based on past experience by operation. One step further than Preventive Maintenance is represented by Predictive Maintenance. Whereas Preventive Maintenance bases its schedules on past performance data, a predictive system acquires condition data from the machine to be maintained whilst the machine is in operation. The information obtained from this analysis indicates the condition in real time, provides a diagnosis of wear and shows any trend towards critical conditions. Predictive maintenance mainly consists of the following interventions: - Lubricant analysis; - Collection / analysis of functional parameters, such as motor absorption, flow rate, pressure, temperature, noise, vibration of rotating equipment, thermal efficiency, etc; - Periodical test of lifting systems; - Other operations to acquire sensitive equipment parameters. Predictive Maintenance can reduce the accidental intervention and extend the components life, and, in the end, is increasing the global availability

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

International Nuclear Information System (INIS)

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

Maintenance Management Update.

Science.gov (United States)

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)

Status on system inspection and preventive maintenance of HANARO

International Nuclear Information System (INIS)

Kim, Young-Ki; Cho, Yeong-Garp; Kwag, Byung-Ho

1999-01-01

The HANARO is a 30 MW open pool type multi-purpose research reactor with forced light water coolant/moderator flows and heavy water annular reflector. The relatively small reactor core uses a low enriched fuel and is designed to maximize the power density, thus providing the required neutron flux for various research activities. It is mainly used for radioisotope production, nuclear material testing and neutron physics experiments. The initial criticality was achieved February 1995. Considering the importance of their functionality from the safety point of view, some components and equipment are categorized into a nuclear safety grade. There are three different inspection activities for the various reactor systems and components - a Surveillance Inspection(SI) for the safety grades and a Periodic Inspection (PI) for the non-safety grades and In-Service Inspection (ISI) for the ASME Sec.III components. All of the SIs are specified and required by the safety analysis report. The SI also differs from the PI in such a point that all kinds of activities for the SIs should be accompanied by an appropriate quality assurance, while for the PIs it is not necessarily mandatory. In addition, the inspection results for the SIs should go through an examination from regulatory body every two years and specific functions of the critical components or systems are demonstrated under the witness by the governmental inspector. The ISI is required and carried out as per international codes and standards as well as Korean atomic energy regulations. There are 54 SIs, 25 PIs and 4 ISIs for the HANARO. This paper concentrates on the managing strategy and its practices for the SIs and ISIs of the safety-related components, currently being done at HANARO. Most parts of the inspections fall into a group for the periodic performance testing and/or equipment calibration. Some mechanical inspections like a torque measurement are grouped into a preventive maintenance. Lastly the ASME Sec

Complete guide to preventive and predictive maintenance

CERN Document Server

Levitt, Joel

2011-01-01

This book shares the best practices, mistakes, victories, and essential steps for success which the author has gleaned from working with countless organizations. Unlike other books that only focus on the engineering issues (task lists) or management issues (CMMS), this in-depth resource is the first to give true emphasize to the four aspects of success in preventive maintenance systems - engineering, management, economic, and psychological - thereby enabling readers to have a balanced view and understanding of what is happening in their organizations. Additionally, it blends concrete actionable steps and structures with the theory behind the steps. It includes check sheets, history of PM, stories, photographs, and case histories. It contains a glossary of terms. It provides sample task lists for a variety of equipment with some of the logic behind each task. It offers templates for developing your own tasking. It includes protocols for detailed economic analysis with examples.

The right maintenance on the right components, at the right time, with the right parts: maintaining high plant reliability through an effective maintenance program

International Nuclear Information System (INIS)

Von Hatten, P.

2008-01-01

The objective of the maintenance program at a Nuclear Power Plant is to be proactive and prevent unexpected failures of equipment that can impact on Nuclear or Conventional Safety and Plant Production. This does not mean that all equipment failures will be prevented; in a number of cases the most cost effective solution is to allow equipment to run to failure. Deciding what components are critical to the plant is the first step. The industry uses guidance from INPO Advanced Process, AP913, to classify components as Critical, Non Critical or Run to Failure based on the consequence of the failure. Once this is complete, then the right maintenance program needs to be specified. This is done through utilization of experience from the industry based on the type of component. Maintenance strategies and templates have been produced for most power plant components. Each station or fleet needs then to apply the criteria, with exceptions as required, to determine the maintenance requirements and frequency for their components. This includes predictive and preventative maintenance. The more critical the component is the more rigorous the maintenance requirements. Once the maintenance program is defined it can be implemented. This requires that the Preventative Maintenance (PM's) are updated to ensure the correct tasks are in place and the frequency is correct. Work Management will group the PM's so they can scheduled efficiently and to minimize equipment down time. The last element is to ensure that the required parts are specified and are stocked or readily available for the maintenance when it is scheduled. This is an ongoing effort since components become obsolete or suppliers go out of business or change hands. (author)

Preventive maintenance instrumentation results in Spanish nuclear power plants

International Nuclear Information System (INIS)

Palomo Anaya, M. Jose; Verdu Martin, Gumersindo; Arnaldos Gonzalvez, Adoracion; Nieva, Marcelino Curiel

2011-01-01

This paper is a recompilation of the most significant results in relation to the researching in Preventive and Predictive Maintenance in critical nuclear instrumentation for power plant operation, which it is being developed by Logistica y Acondicionamientos Industriales and The Isirym Institute of the Polytechnic University of Valencia. Instrumentation verification and test, it is a priority of the Power Plants Control and Instrumentation Department technicians. These procedures are necessary information for the daily power plant work. It is performed according to different procedures and in different moments of the fuel cycle depending on the instrumentation critical state and the monitoring process. Normally, this study is developed taking into account the instantaneous values of the instrumentation measures and, after their conversion to physical magnitude, they are analyzed according to the power plant operation point. Moreover, redundant sensors measurements are taken into consideration to the equipment and/or power plant monitoring. This work goes forward and it is in advanced to the instrument analysis as it is, independently of the operation point, using specific signal analysis techniques for preventive and predictive maintenance, with the aim to obtain not only information about possible malfunctions, but the degradation scale presented in the instrument or in the system measured. We present seven real case studies of Spanish Nuclear Power Plants each of them shall give a significant contribution to problem resolution and power plant performance: Fluctuations in sensor lines (case 1), Air presence in feed water lines (case 2), Root valve partially closed (case 3), Sensor malfunctions (case 4), Electrical source malfunctions (case 5), RTD malfunctions (case 6) and LPRM malfunctions (case 7). (author)

Preventive maintenance instrumentation results in Spanish nuclear power plants

Energy Technology Data Exchange (ETDEWEB)

Palomo Anaya, M. Jose; Verdu Martin, Gumersindo, E-mail: mpalomo@iqn.upv.es, E-mail: gverdu@iqn.upv.es [ISIRYM Universidad Politecnica de Valencia, Valencia (Spain); Arnaldos Gonzalvez, Adoracion, E-mail: a.arnaldos@titaniast.com [TITANIA Servicios Tecnologicos SL, Valencia (Spain); Nieva, Marcelino Curiel, E-mail: m.curiel@lainsa.com [Logistica y Acondicionamientos Industriales SAU (LAINSA), Valencia (Spain)

2011-07-01

This paper is a recompilation of the most significant results in relation to the researching in Preventive and Predictive Maintenance in critical nuclear instrumentation for power plant operation, which it is being developed by Logistica y Acondicionamientos Industriales and The Isirym Institute of the Polytechnic University of Valencia. Instrumentation verification and test, it is a priority of the Power Plants Control and Instrumentation Department technicians. These procedures are necessary information for the daily power plant work. It is performed according to different procedures and in different moments of the fuel cycle depending on the instrumentation critical state and the monitoring process. Normally, this study is developed taking into account the instantaneous values of the instrumentation measures and, after their conversion to physical magnitude, they are analyzed according to the power plant operation point. Moreover, redundant sensors measurements are taken into consideration to the equipment and/or power plant monitoring. This work goes forward and it is in advanced to the instrument analysis as it is, independently of the operation point, using specific signal analysis techniques for preventive and predictive maintenance, with the aim to obtain not only information about possible malfunctions, but the degradation scale presented in the instrument or in the system measured. We present seven real case studies of Spanish Nuclear Power Plants each of them shall give a significant contribution to problem resolution and power plant performance: Fluctuations in sensor lines (case 1), Air presence in feed water lines (case 2), Root valve partially closed (case 3), Sensor malfunctions (case 4), Electrical source malfunctions (case 5), RTD malfunctions (case 6) and LPRM malfunctions (case 7). (author)

Integrated maintenance program (IMP)

International Nuclear Information System (INIS)

Zemdegs, R.T.; Chout, Q.B.

1998-01-01

Approaches to the maintenance of nuclear power plants have undergone significant change in the past several decades. The traditional breakdown approach has been displaced by preventive (calendar-based) maintenance and more recently, by condition-based maintenance (CBM). This is largely driven by the fact that traditional maintenance programs, derived primarily from equipment vendor recommendations, are generally unsuccessful in controlling maintenance costs or equipment failures. Many advances in the maintenance field have taken place since the maintenance plans for Ontario Hydro's nuclear plants were initially established. Ontario Hydro nuclear plant operating costs can be substantially reduced and Incapability Factor improved with the application of modern maintenance processes and tools. Pickering is designated as the lead station for IMP. Of immediate concern is the fact that Pickering Nuclear Division has been experiencing a significant backlog of Operating Preventive Maintenance Callups. This backlog, over 2000, is unacceptable to both station management and the nuclear regulator, the Atomic Energy Control Board. In addition there are over 500 callups in various stages of revision (in hyperspace) without an adequate control nor reporting system to manage their completion. There is also considerable confusion about the classification of l icensing c allups, e.g. callups which are mandatory as a result of legal requirements. Furthermore the ineffectiveness of the Preventive Maintenance (PM) has been the subject of peer audits and Atomic Energy Control Board (AECB) findings over the past several years. The current preventive maintenance ratio PM2 /(PM+CM3) at Pickering ND is less than 20%, due to the current high load of equipment breakdown. This past summer, an Independent Integrated Performance Assessment (IIPA) review at Ontario Hydro confirmed these concerns. Over the past several years, Ontario Hydro nuclear staff have evaluated several programs to improve

Webinar: Making the Connection: Linking IAQ, Energy Efficiency and Preventive Maintenance Together for Healthy Schools

Science.gov (United States)

A page to register to view the February 22, 2018, Energy Savings Plus Health for Schools Webinar Series Webinar: Making the Connection: Linking IAQ, Energy Efficiency and Preventive Maintenance Together for Healthy Schools

Condition-based maintenance for complex systems : Coordinating maintenance and logistics planning for the process industries

NARCIS (Netherlands)

Olde Keizer, Minou Catharina Anselma

2016-01-01

Maintenance planning in the process industries is extremely complex for various reasons. Plants often run nonstop, allowing little time for performing preventive maintenance. Failures should be prevented, however, as they can lead to system downtime and high losses of revenue. Corrective maintenance

JRR-3 maintenance program utilizing accumulated maintenance data

International Nuclear Information System (INIS)

Izumo, Hironobu; Kato, Tomoaki; Kinase, Masami; Torii, Yoshiya; Murayama, Yoji

2007-07-01

JRR-3(Japan Research Reactor No.3) has been operated for more than 15 years after the modification, without significant troubles by carrying out maintenance such as the preventive maintenance (mainly time-based maintenance) for the safety-grade equipments and the breakdown maintenance for the non-safety-grade equipments. Unscheduled shutdowns causes by aged non-safety-grade equipments have been increasing, and the resources such as budgets have been decreasing year by year. In this situation, JRR-3 maintenance program was reviewed about safety, reliability and economic efficiency. This report offers the policy of the maintenance review and the future direction of maintenance programs. (author)

Principal scheme of preventive maintenance support system for nuclear power plants

International Nuclear Information System (INIS)

Nishiyama, Takuya; Terano, Takao; Yokoo, Takeshi; Shinohara, Yasushi

1985-01-01

It is of great importance to turn lessons learned from abnormal event experiences to advantage as well as taking apriori actions for prevention of abnormal events in nuclear power plants. From this point of view, a consultation system, named as Preventive Maintenance Support System (PMSS), which is to possess accumulated knowledges drawn from the past abnormal events in nuclear power plants infer occurrences, factors and developments of abnormal events and recommend preventive countermeasures on the basis of the knowledges, has been proposed. This report presents the principal scheme of PMSS. To begin with, following to the discussion of the purpose and use of PMSS, the fundamental functions PMSS should perform are specified. They are (1) event factors analyzation, (2) event prediction (event development estimation and analogous event estimation), (3) event significance evaluation and (4) preventive countermeasures presentation. In the next place, it is asserted that such a system should be constructed as a knowledge engineering one. Then, the R and D subjects and related schedule for PMSS are set up. (author)

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

Science.gov (United States)

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.

Master--slave manipulators and remote maintenance at the Oak Ridge National Laboratory

International Nuclear Information System (INIS)

Jenness, R.G.; Wicker, C.D.

1975-01-01

The volume of master-slave manipulator maintenance at Oak Ridge National Laboratory has necessitated the establishment of a repair facility and the organization of a specially trained group of craftsmen. Emphasis on cell containment requires the use of manipulator boots and the development of precise procedures for accomplishing the maintenance of 283 installed units. To provide the most economical type of preventive maintenance, a very satisfactory computer-programmed maintenance system has been established at the Laboratory. (auth)

Interval of Routine Maintenance and Maintenance Performance: A Literature Review

Directory of Open Access Journals (Sweden)

Au-Yong Cheong Peng

2016-01-01

Full Text Available In high-rise residential buildings, the quality of facilities management services is significant to the normal operation of the facilities. Unfortunately, lack of concern towards building maintenance, especially preventive maintenance, happens in domestic housing industry in Malaysia. Majority of the maintenance operations of condominiums suffer from lack of planning, lack of proactive maintenance plan, and lack of proper implementation. Thus, this paper reviews the implementation of preventive maintenance strategy, routine maintenance in specific. An extensive review of literature published in 1987 to 2014 is performed for the purpose of this research. The publications are sourced from journal articles, conference proceedings and books. The literature analysis confirms that the routine maintenance of facilities and building services is vital and it can be influential towards the maintenance performance. Subsequently, a theoretical framework is developed, which shows the relationship between routine maintenance of building facilities & services and maintenance performance. The building facilities & services are divided into two categories. They are essential facilities & services that ensure the safety, health, habitability, and operability of buildings; while value-added facilities & services deal with property value, return on investment, and quality living of buildings. Based on the findings, a future research is proposed, which aims to identify the appropriate routine of maintenance for the facilities and services in high-rise residential buildings to improve the maintenance performance.

Environmental Restoration Program pollution prevention checklist guide for the surveillance and maintenance project phase

International Nuclear Information System (INIS)

1993-09-01

DOE Order 5820.2 mandates that a surveillance and maintenance program be established in all shut-down facilities to ensure adequate containment of contamination, provide physical safety and security, and reduce potential public and environmental hazards. A key consideration in this process is the prevention of any waste to be generated from these activities. The purpose of this checklist guide is to assist the user with incorporating pollution prevention/waste minimization (PP/WM) in all Surveillance and Maintenance (S ampersand M) phase projects of the Environmental Restoration (ER) Program. This guide will help users document their PP/WM activities for technology transfer and reporting requirements. Automated computer screens will be created from the checklist data to assist users with implementing and evaluating waste reduction. Users can then establish numerical performance measures to measure progress in planning, training, self-assessments, field implementation, documentation, and technology transfer. Cost savings result as users train and assess themselves and perform preliminary waste assessments

Corrective maintenance support system for nuclear power plants

International Nuclear Information System (INIS)

Kakiuchi, Tetsuo

1996-01-01

With increase of share of nuclear power generation in electric power supply in Japan, requirement for further safe operation and improvement of economics for the nuclear power plants is promoting. The pressed water type (PWR) nuclear power plant in operation in Japan reaches to 22 sets, application rate of the instruments is 74% as mean value for 7 years since 1989 and in high level, which is due to a result of preventive maintenance in ordinary and periodical inspections. The present state of maintenance at the nuclear power plant is mainly preventive maintenance, which is mainly conducted in a shape of time planning maintenance but partially in a shape of state monitoring maintenance for partial rotating appliances. Concretely speaking, the periodical inspection was planned on a base of daily inspection and a long term program on maintenance, and executed on a base of feedback function to think of the long term program again by evaluating the periodical inspection results. Here were introduced on the monitoring diagnosis and periodical inspection regionalization equipment, fatigue monitoring system, automatic supersonic wave damage inspection equipment for reactor, steam evaporator heat conductive tube inspection equipment, automatic testing equipment for measuring controller, air working valve property testing equipment, as maintaining support system in the PW generation plant. (G.K.)

Systematic analysis and prevention of human originated common cause failures in relation to maintenance activities at Finnish nuclear power plants

Energy Technology Data Exchange (ETDEWEB)

Laakso, K. [VTT Industrial Systems, Espoo (Finland)

2006-12-15

The focus in human reliability analysis of nuclear power plants has traditionally been on human performance in disturbance conditions. On the other hand, human maintenance failures and design deficiencies, remained latent in the system, have an impact on the severity of a disturbance, e.g. by disabling safety-related equipment on demand. Especially common cause failures (CCFs) of safety related systems can affect the core damage risk to a significant extent. The topic has been addressed in Finnish studies, where experiences of latent human errors have been searched and analysed systematically from the maintenance history stored in the the power plant information systems of the Loviisa and Olkiluoto NPPs. Both the single and multiple errors (CCFs) were classified in detail and documented as error and event reports. The human CCFs involved human, organisational and technical factors. The review of the analysed single and multiple errors showed that instrumentation and control and electrical equipment are more prone to human error caused failure events than the other maintenance objects. The review of the analysed experience showed that most errors stem from the refuelling and maintenance outage periods. More than half of the multiple errors from the outages remained latent to the power operating periods. The review of the analysed multiple errors showed that difficulties with small plant modifications and planning of maintenance and operability were significant sources of common cause failures. The most dependent human errors originating from small modifications could be reduced by a more tailored planning and coverage of their start-up testing programs. Improvements could also be achieved by identifying better in work planning from the operating experiences those complex or intrusive repair and preventive maintenance work tasks and actions which are prone to errors. Such uncertain cases in important equipment require a more tailored work planning of the installation

Systematic analysis and prevention of human originated common cause failures in relation to maintenance activities at Finnish nuclear power plants

International Nuclear Information System (INIS)

Laakso, K.

2006-12-01

The focus in human reliability analysis of nuclear power plants has traditionally been on human performance in disturbance conditions. On the other hand, human maintenance failures and design deficiencies, remained latent in the system, have an impact on the severity of a disturbance, e.g. by disabling safety-related equipment on demand. Especially common cause failures (CCFs) of safety related systems can affect the core damage risk to a significant extent. The topic has been addressed in Finnish studies, where experiences of latent human errors have been searched and analysed systematically from the maintenance history stored in the the power plant information systems of the Loviisa and Olkiluoto NPPs. Both the single and multiple errors (CCFs) were classified in detail and documented as error and event reports. The human CCFs involved human, organisational and technical factors. The review of the analysed single and multiple errors showed that instrumentation and control and electrical equipment are more prone to human error caused failure events than the other maintenance objects. The review of the analysed experience showed that most errors stem from the refuelling and maintenance outage periods. More than half of the multiple errors from the outages remained latent to the power operating periods. The review of the analysed multiple errors showed that difficulties with small plant modifications and planning of maintenance and operability were significant sources of common cause failures. The most dependent human errors originating from small modifications could be reduced by a more tailored planning and coverage of their start-up testing programs. Improvements could also be achieved by identifying better in work planning from the operating experiences those complex or intrusive repair and preventive maintenance work tasks and actions which are prone to errors. Such uncertain cases in important equipment require a more tailored work planning of the installation

Roles of Type 1A Topoisomerases in Genome Maintenance in Escherichia coli

Science.gov (United States)

Usongo, Valentine; Drolet, Marc

2014-01-01

In eukaryotes, type 1A topoisomerases (topos) act with RecQ-like helicases to maintain the stability of the genome. Despite having been the first type 1A enzymes to be discovered, much less is known about the involvement of the E. coli topo I (topA) and III (topB) enzymes in genome maintenance. These enzymes are thought to have distinct cellular functions: topo I regulates supercoiling and R-loop formation, and topo III is involved in chromosome segregation. To better characterize their roles in genome maintenance, we have used genetic approaches including suppressor screens, combined with microscopy for the examination of cell morphology and nucleoid shape. We show that topA mutants can suffer from growth-inhibitory and supercoiling-dependent chromosome segregation defects. These problems are corrected by deleting recA or recQ but not by deleting recJ or recO, indicating that the RecF pathway is not involved. Rather, our data suggest that RecQ acts with a type 1A topo on RecA-generated recombination intermediates because: 1-topo III overproduction corrects the defects and 2-recQ deletion and topo IIII overproduction are epistatic to recA deletion. The segregation defects are also linked to over-replication, as they are significantly alleviated by an oriC::aph suppressor mutation which is oriC-competent in topA null but not in isogenic topA+ cells. When both topo I and topo III are missing, excess supercoiling triggers growth inhibition that correlates with the formation of extremely long filaments fully packed with unsegregated and diffuse DNA. These phenotypes are likely related to replication from R-loops as they are corrected by overproducing RNase HI or by genetic suppressors of double topA rnhA mutants affecting constitutive stable DNA replication, dnaT::aph and rne::aph, which initiates from R-loops. Thus, bacterial type 1A topos maintain the stability of the genome (i) by preventing over-replication originating from oriC (topo I alone) and R-loops and (ii

Maintenance Staffing Standards for Zero-Based Budgeting.

Science.gov (United States)

Adams, Matthew C.; And Others

1998-01-01

Discusses school preventive maintenance and the variables associated with maintenance staffing standards that address a zero-based budgeting environment. Explores preventive-maintenance measurement for staffing requirements, defines staffing levels and job descriptions, and outlines the factors to consider when creating a maintenance program and…

Preventative maintenance of drainpipes in radioisotope facility using flexible hose

International Nuclear Information System (INIS)

Hiroi, Tomoko; Tatsunami, Shinobu; Kuwabara, Rie; Kouyama, Hiroshi; Matsui, Hiroaki; Yamamoto, Takio

2009-01-01

A flexible hose made of plasticized polyvinyl chloride was introduced into underground radioactive wastewater drainpipes as preventative maintenance. We completed a seamless connection spanning the longest interval between the last confluence point and the wastewater tank. Although the flexible hose is not a construction material but rather a consumable article, it is robust against the effects of temperature change and erosion by chemical substances. Moreover, it is placed in an underground steel pipe where it is protected from UV irradiation and friction. Therefore, increased hose durability is expected. In addition, the risk of damage from earthquakes or ground subsidence is negligible due to the flexibility of the hose. Compared with a full renovation of the plumbing, the economic cost is much cheaper and the construction period is much shorter. We propose the use of flexible hoses as one of the most convenient methods to prevent leakage accidents at radioisotope facilities with underground plumbing for wastewater. (author)

Methods and tools in development in the field of maintenance; Methodes et outils pour la maintenance en cours de developpement

Energy Technology Data Exchange (ETDEWEB)

Le Reverend, D.; Tortolano, M. [Electricite de France (EDF/RD), 78 - Chatou (France); Leniaud, F. [Electricite de France (EDF), Div. Production Nuleaire, 93 - Saint-Denis (France)

2004-07-01

This article is dedicated to the maintenance strategy followed by EDF for its nuclear power plants. This strategy is based on the American method RCM (reliability centered method) that has been extended to passive components such as structures and relies on 4 axis. The first axis can be defined as the optimization of maintenance with regard to safety, outage and costs. The aim is to set the border between preventive maintenance and remedial maintenance. The second axis is the condition based maintenance that is the maintenance action that is triggered by the real state of the equipment. This type of maintenance implies the search for reliable and accurate diagnostics. The third axis is the design of simulation and planning tools required for the management of the moving of tools, machinery and spare-parts on a maintenance work site. The fourth axis is the design of tools able to repair some important equipment, this way may be a valid alternative to the replacement of equipment in terms of cost and outage time. (A.C.)

Maintenance Management Support Systems for component aging estimation at nuclear power plants

International Nuclear Information System (INIS)

Shimizu, Shunichi; Ando, Yasumasa; Morioka, Toshihiko; Okuzumi, Naoaki

1991-01-01

Maintenance Management Support Systems (MMSSs) for nuclear power plants have been developed using component aging estimation methods and decision tree analysis for maintenance planning. The former evaluates actual component reliability through statistical analysis on field maintenance data. The latter provides preventive maintenance (PM) planning guidance using heuristic expert knowledge and estimated reliability parameters. The following aspects have been investigated: (1) A systematic and effective method of managing components/parts design information and field maintenance data (2) A method for estimating component aging based on a statistical analysis of field maintenance data (3) A method for providing PM planning guidance using estimated component reliability/performance parameters and decision tree analysis. Based on these investigations, two MMSSs were developed. One deals with 'general maintenance data', which are common to all component types and are amenable to common data handling. The other system deals with 'specific maintenance data', which are specific to an individual component type. Both systems provide PM planning guidance for PM cycles propriety and the PM work priority. The function of these systems were verified using simulated maintenance data. (author)

Instrumentation maintenance

International Nuclear Information System (INIS)

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

Preventative maintenance cycle of contact switches for nuclear power plants based on lifetime assessment and economic analysis

International Nuclear Information System (INIS)

Shi Jie

2010-01-01

An approach to determine the preventive maintenance cycle was proposed in consideration of the lifetime, optimal cost and economy. Two parameters Weibull distribution was used to calculate the lifetime of contact switch. The block replacement model and age replacement model were built with the objective of optimal cost, and the preventive replacement cycle was accounted. Eight proposals for preventive replacement cycle were given. Economy model was applied to assess those proposals and the optimal proposal was confirmed. (authors)

Electrical predictive maintenance at Trillo I Nuclear Power Plant

International Nuclear Information System (INIS)

Vicente, L. R.; Fernandez de la Mata, R.; Cano Gonzalez, J. C.

1998-01-01

An electrical predictive maintenance plan is currently being put into effect at Trillo I Nuclear Power Plant which is initially being applied to three types of equipment: motors, transformers and motor-driven valves. This paper describes the different phases considered in the implementation of the Predictive Maintenance Plan: study of existing techniques for such equipment (tangoδ, spectral analysis of stator current, chromatographic analysis of gases, spectral analysis of the axial stray magnetic flux, etc), study of the special characteristics of the electrical equipment at Trillo NPP, analysis of applicable techniques (characteristic parameters, alert-alarm values, experience with such techniques, etc), analysis of machine history records, study of the optimum preventive-predictive case, study of applicable frequencies and definition of the computerised predictive maintenance management tool. With the exception of the computerised predictive maintenance management applications which are presently being implemented, all the activities described above have been carried out on the three types of equipment mentioned. (Author)

Numerical study of inventory management under various maintenance policies

NARCIS (Netherlands)

Poppe, J.; Basten, R.J.I.; Boute, R.N.; Lambrecht, M.R.

2017-01-01

Capital assets, such as manufacturing equipment, require maintenance to remain functioning. Maintenance can be performed when a component breaks down and needs replacement (i.e., corrective maintenance), or the maintenance and part replacement can be performed preventively. Preventive maintenance

Maintenance cost models in deregulated power systems under opportunity costs

International Nuclear Information System (INIS)

Al-Arfaj, K.; Dahal, K.; Azaiez, M.N.

2007-01-01

In a centralized power system, the operator is responsible for scheduling maintenance. There are different types of maintenance, including corrective maintenance; predictive maintenance; preventive maintenance; and reliability-centred maintenance. The main cause of power failures is poor maintenance. As such, maintenance costs play a significant role in deregulated power systems. They include direct costs associated with material and labor costs as well as indirect costs associated with spare parts inventory, shipment, test equipment, indirect labor, opportunity costs and cost of failure. In maintenance scheduling and planning, the cost function is the only component of the objective function. This paper presented the results of a study in which different components of maintenance costs were modeled. The maintenance models were formulated as an optimization problem with single and multiple objectives and a set of constraints. The maintenance costs models could be used to schedule the maintenance activities of power generators more accurately and to identify the best maintenance strategies over a period of time as they consider failure and opportunity costs in a deregulated environment. 32 refs., 4 tabs., 4 figs

JIT single machine scheduling problem with periodic preventive maintenance

Science.gov (United States)

Shahriari, Mohammadreza; Shoja, Naghi; Zade, Amir Ebrahimi; Barak, Sasan; Sharifi, Mani

2016-09-01

This article investigates a JIT single machine scheduling problem with a periodic preventive maintenance. Also to maintain the quality of the products, there is a limitation on the maximum number of allowable jobs in each period. The proposed bi-objective mixed integer model minimizes total earliness-tardiness and makespan simultaneously. Due to the computational complexity of the problem, multi-objective particle swarm optimization (MOPSO) algorithm is implemented. Also, as well as MOPSO, two other optimization algorithms are used for comparing the results. Eventually, Taguchi method with metrics analysis is presented to tune the algorithms' parameters and a multiple criterion decision making technique based on the technique for order of preference by similarity to ideal solution is applied to choose the best algorithm. Comparison results confirmed the supremacy of MOPSO to the other algorithms.

Maintenance technologies for reactor internals

Energy Technology Data Exchange (ETDEWEB)

Sato, Kenji [Nuclear Energy Systems and Services Div., Toshiba Corp., Tokyo (Japan); Kobayashi, Masahiro [Toshiba Corp., Yokohama (Japan). Keihin Product Operations; Sano, Yuji; Kimura, Seiichiro [Power and Industrial Systems Research and Development Center, Toshiba Corp., Tokyo(Japan)

2000-10-01

Toshiba places the highest priority on maintenance technologies for the reactor pressure vessel (RPV) and its internals in operating nuclear power plants. This paper summarizes the status of applied laser maintenance technologies, both preventive and repair. For laser peeing and laser desensitization treatment (LDT) technologies in particular, field applications are also described in detail. In the future, the area of field applications for preventive maintenance, repair, and inspection technologies will be further expanded. (author)

An overview of a knowledge based system for preventive maintenance support of nuclear power plants

International Nuclear Information System (INIS)

Terano, Takao; Nishiyama, Takuya; Yokoo, Takeshi

1984-01-01

In recent years, much interest has been paid to knowledge engineering techniques for new vehicles of advanced information processing. As a practical application in electric power industry, this report discusses a knowledge based system for supporting preventive maintenance of nuclear power plants. To support preventive maintenance tasks, the system must have facilities to reason failures and accidents of the plants, to evaluate their significance, to predict any possible troubles, and to indentify appropriate preventive countermeasures for them. This report describes the overview of the prototype system from a viewpoint of knowledge engineering. The results of the study are as follows: (1) The knowledge base of the prototype system consists of a data-base on plants and a rule-base derived from experts' knowledge. Using the information in the knowledge base, the system diagnoses the plant without real-time interaction with operational plants. (2) Expert's knowledge in the rule-base is represented in the non-procedural declarative forms. These rules are organized in some hierarchical structure so as to be used efficiently and used in conjunction with the corresponding set of plant information in the data-base. (3) The prototype system is incrementally developed with the rapid prototyping techniques, that is, the processes of design, implementation and evaluation are repeated several times. (author)

Maintenance of nuclear power plants

International Nuclear Information System (INIS)

1982-01-01

This Guide covers the organizational and procedural aspects of maintenance but does not give detailed technical advice on the maintenance of particular plant items. It gives guidance on preventive and remedial measures necessary to ensure that all structures, systems and components important to safety are capable of performing as intended. The Guide covers the organizational and administrative requirements for establishing and implementing preventive maintenance schedules, repairing defective plant items, providing maintenance facilities and equipment, procuring stores and spare parts, selecting and training maintenance personnel, reviewing and controlling plant modifications arising from maintenance, and for generating, collecting and retaining maintenance records. Maintenance shall be subject to quality assurance in all aspects important to safety. Because quality assurance has been dealt with in detail in other Safety Guides, it is only included here in specific instances where emphasis is required. Maintenance is considered to include functional and performance testing of plant, surveillance and in-service inspection, where these are necessary either to support other maintenance activities or to ensure continuing capability of structures, systems and components important to safety to perform their intended functions

Planning of maintenance of electrical equipment in nuclear plants/laboratories [Paper No.: VB-3

International Nuclear Information System (INIS)

Narasinga Rao, S.N.; Bhattacharyya, A.K.

1981-01-01

Satisfactory operating performance of electrical systems ensures continuous availability of power to the various plants and machinery in nuclear plant and laboratories. For effective optimal functioning of the electrical equipment and to reduce their down time, scheduled planning of maintenance to the equipment is essential. Maintenance of power plant, nuclear or fossil, and industrial plant and research laboratories demands essential ingredients such as right type of trained and motivated technical personnel, adoption of standard procedures for maintenance, adequate safety and protection for equipment, safety procedures adopted in the installation to prevent hazards to the workers, provision of adequate stores and inventories, facilities for quick repairs and testing of equipment and effective planning of procedures for their maintenance. While breakdown maintenance allows equipment to operate before it is repaired or replaced, preventive maintenance makes use of scheduled inspection and periodical equipment overhaul and has little value for predicting future continuous performances of equipment. The engineered maintenance is most advantageous and offers maximum operating time to reduce down time of the equipment while adding predictive testing technique to aid in determining the frequency of overhaul of equipment. The important checks to be conducted and preventive maintenance programme to be scheduled are discussed in this paper. The safety and reliable functioning of the electrical equipment depend on proper optimal design, selection of equipment, their installation, subsequent maintenance and strict compliance with safety regulations. (author)

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

Science.gov (United States)

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%.

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

International Nuclear Information System (INIS)

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.

Maintenance of systemic immune functions prevents accelerated presbycusis.

Science.gov (United States)

Iwai, Hiroshi; Baba, Susumu; Omae, Mariko; Lee, Shinryu; Yamashita, Toshio; Ikehara, Susumu

2008-05-07

There is no effective therapy for progressive hearing loss such as presbycusis, the causes of which remain poorly understood because of the difficulty of separating genetic and environmental contributions. In the present study, we show that the age-related dysfunctions of the systemic immune system in an animal model of accelerated presbycusis (SAMP1, senescence-accelerated mouse P1) can be corrected by allogeneic bone marrow transplantation (BMT). We also demonstrate that this presbycusis can be prevented; BMT protects the recipients from age-related hearing impairment and the degeneration of spiral ganglion cells (SGCs) as well as the dysfunctions of T lymphocytes, which have a close relation to immune senescence. No donor cells are infiltrated to the spiral ganglia, confirming that this experimental system using BMT is connected to the systemic immune system and does not contribute to transdifferentiation or fusion by donor hematopoietic stem cells (HSCs), or to the direct maintenance of ganglion cells by locally infiltrated donor immunocompetent cells. Therefore, another procedure which attempts to prevent the age-related dysfunctions of the recipient immune system is the inoculation of syngeneic splenocytes from young donors. These mice show no development of hearing loss, compared with the recipient mice with inoculation of saline or splenocytes from old donors. Our studies on the relationship between age-related systemic immune dysfunctions and neurodegeneration mechanisms open up new avenues of treatment for presbycusis, for which there is no effective therapy.

A probabilistic maintenance model for diesel engines

Science.gov (United States)

Pathirana, Shan; Abeygunawardane, Saranga Kumudu

2018-02-01

In this paper, a probabilistic maintenance model is developed for inspection based preventive maintenance of diesel engines based on the practical model concepts discussed in the literature. Developed model is solved using real data obtained from inspection and maintenance histories of diesel engines and experts' views. Reliability indices and costs were calculated for the present maintenance policy of diesel engines. A sensitivity analysis is conducted to observe the effect of inspection based preventive maintenance on the life cycle cost of diesel engines.

Maintenance management for nuclear power plant 'Integrated valve maintenance'

International Nuclear Information System (INIS)

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

Risk-based Operation and Maintenance for Offshore Wind Turbines

DEFF Research Database (Denmark)

Sørensen, John Dalsgaard; Nielsen, Jannie Jessen

2011-01-01

For offshore wind turbines, costs to Operation and Maintenance (OM) are substantial, and can be expected to increase when wind farms are placed at deeper water depths and in more harsh environments. Traditional strategies for OM include corrective and preventive (scheduled and condition...... statistics and costs of the different operations. The different OM strategies are described and compared in an illustrative example with focus on which types of information that are needed. Special focus is on comparison between risk-based maintenance strategies and the conventional maintenance planning...... and are often the driving mechanisms for failures / faults that need maintenance. Observations of the degree of damage can increase the reliability of predictions and decrease the costs of OM if integrated in a risk-based framework theoretically based on pre-posterior Bayesian decision theory. The mathematical...

Component-Based Data-Driven Predictive Maintenance to Reduce Unscheduled Maintenance Events

NARCIS (Netherlands)

Verhagen, W.J.C.; Curran, R.; de Boer, L.W.M.; Chen, C.H.; Trappey, A.C.; Peruzzini, M.; Stjepandić, J.; Wognum, N.

2017-01-01

Costs associated with unscheduled and preventive maintenance can contribute significantly to an airline's expenditure. Reliability analysis can help to identify and plan for maintenance events. Reliability analysis in industry is often limited to statistically based

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

Science.gov (United States)

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.

Study on the methodology for predicting and preventing errors to improve reliability of maintenance task in nuclear power plant

International Nuclear Information System (INIS)

Hanafusa, Hidemitsu; Iwaki, Toshio; Embrey, D.

2000-01-01

The objective of this study was to develop and effective methodology for predicting and preventing errors in nuclear power plant maintenance tasks. A method was established by which chief maintenance personnel can predict and reduce errors when reviewing the maintenance procedures and while referring to maintenance supporting systems and methods in other industries including aviation and chemical plant industries. The method involves the following seven steps: 1. Identification of maintenance tasks. 2. Specification of important tasks affecting safety. 3. Assessment of human errors occurring during important tasks. 4. Identification of Performance Degrading Factors. 5. Dividing important tasks into sub-tasks. 6. Extraction of errors using Predictive Human Error Analysis (PHEA). 7. Development of strategies for reducing errors and for recovering from errors. By way of a trial, this method was applied to the pump maintenance procedure in nuclear power plants. This method is believed to be capable of identifying the expected errors in important tasks and supporting the development of error reduction measures. By applying this method, the number of accidents resulting form human errors during maintenance can be reduced. Moreover, the maintenance support base using computers was developed. (author)

Modern electronic maintenance principles

CERN Document Server

Garland, DJ

2013-01-01

Modern Electronic Maintenance Principles reviews the principles of maintaining modern, complex electronic equipment, with emphasis on preventive and corrective maintenance. Unfamiliar subjects such as the half-split method of fault location, functional diagrams, and fault finding guides are explained. This book consists of 12 chapters and begins by stressing the need for maintenance principles and discussing the problem of complexity as well as the requirements for a maintenance technician. The next chapter deals with the connection between reliability and maintenance and defines the terms fai

Effectiveness and cost-effectiveness of mindfulness-based cognitive therapy compared with maintenance antidepressant treatment in the prevention of depressive relapse or recurrence (PREVENT): a randomised controlled trial.

Science.gov (United States)

Kuyken, Willem; Hayes, Rachel; Barrett, Barbara; Byng, Richard; Dalgleish, Tim; Kessler, David; Lewis, Glyn; Watkins, Edward; Brejcha, Claire; Cardy, Jessica; Causley, Aaron; Cowderoy, Suzanne; Evans, Alison; Gradinger, Felix; Kaur, Surinder; Lanham, Paul; Morant, Nicola; Richards, Jonathan; Shah, Pooja; Sutton, Harry; Vicary, Rachael; Weaver, Alice; Wilks, Jenny; Williams, Matthew; Taylor, Rod S; Byford, Sarah

2015-07-04

Individuals with a history of recurrent depression have a high risk of repeated depressive relapse or recurrence. Maintenance antidepressants for at least 2 years is the current recommended treatment, but many individuals are interested in alternatives to medication. Mindfulness-based cognitive therapy (MBCT) has been shown to reduce risk of relapse or recurrence compared with usual care, but has not yet been compared with maintenance antidepressant treatment in a definitive trial. We aimed to see whether MBCT with support to taper or discontinue antidepressant treatment (MBCT-TS) was superior to maintenance antidepressants for prevention of depressive relapse or recurrence over 24 months. In this single-blind, parallel, group randomised controlled trial (PREVENT), we recruited adult patients with three or more previous major depressive episodes and on a therapeutic dose of maintenance antidepressants, from primary care general practices in urban and rural settings in the UK. Participants were randomly assigned to either MBCT-TS or maintenance antidepressants (in a 1:1 ratio) with a computer-generated random number sequence with stratification by centre and symptomatic status. Participants were aware of treatment allocation and research assessors were masked to treatment allocation. The primary outcome was time to relapse or recurrence of depression, with patients followed up at five separate intervals during the 24-month study period. The primary analysis was based on the principle of intention to treat. The trial is registered with Current Controlled Trials, ISRCTN26666654. Between March 23, 2010, and Oct 21, 2011, we assessed 2188 participants for eligibility and recruited 424 patients from 95 general practices. 212 patients were randomly assigned to MBCT-TS and 212 to maintenance antidepressants. The time to relapse or recurrence of depression did not differ between MBCT-TS and maintenance antidepressants over 24 months (hazard ratio 0·89, 95% CI 0·67-1·18

Maintenance of radiation monitoring systems

International Nuclear Information System (INIS)

Aoyama, Kei

2001-01-01

As the safety and quality of atomic power facilities are more strongly required, the reliability improvement and preventive maintenance of radiation monitoring systems are important. This paper describes the maintenance of radiation monitoring systems delivered by Fuji Electric and the present status of preventive maintenance technology. Also it introduces the case that we developed a fault diagnosis function adopting a statistics technique and artificial intelligence (AI) and delivered a radiation monitoring system including this function. This system can output a fault analysis result and a countermeasure from the computer in real time. (author)

Performance evaluation of multi-state degraded systems with minimal repairs and imperfect preventive maintenance

International Nuclear Information System (INIS)

Soro, Isaac W.; Nourelfath, Mustapha; Ait-Kadi, Daoud

2010-01-01

In this paper, we develop a model for evaluating the availability, the production rate and the reliability function of multi-state degraded systems subjected to minimal repairs and imperfect preventive maintenance. The status of the system is considered to degrade with use. These degradations may lead to decrease in the system efficiency. It is assumed that the system can consecutively degrade into several discrete states, which are characterized by different performance rates, ranging from perfect functioning to complete failure. The latter is observed when the degradation level reaches a certain critical threshold such as the system efficiency may decrease to an unacceptable limit. In addition, the system can fail randomly from any operational or acceptable state and can be repaired. This repair action brings the system to its previous operational state without affecting its failure rate (i.e., minimal repair). The used preventive maintenance policy suggests that if the system reaches the last acceptable degraded state, it is brought back to one of the states with higher efficiency. Considering customer demand as constant, the system is modeled as a continuous-time Markov process to assess its instantaneous and stationary performance measures. A numerical example is given to illustrate the proposed model.

Advanced maintenance research programs

International Nuclear Information System (INIS)

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

A Biochemical Approach to Understanding the Fanconi Anemia Pathway-Regulated Nucleases in Genome Maintenance for Preventing Bone Marrow Failure and Cancer

Science.gov (United States)

2014-04-01

the Fanconi Anemia Pathway- Regulated Nucleases in Genome Maintenance for Preventing Bone Marrow Failure and Cancer PRINCIPAL INVESTIGATOR...GRANT NUMBER 4. TITLE AND SUBTITLE A Biochemical Approach to Understanding the Fanconi Anemia Pathway-Regulated Nucleases in Genome Maintenance for...Unlimited 13. SUPPLEMENTARY NOTES 14. ABSTRACT Fanconi anemia is the most prevalent inherited BMF syndromes, caused by mutations in

Joint optimization of maintenance, buffers and machines in manufacturing lines

Science.gov (United States)

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.

A Grounded Theory Study of Aircraft Maintenance Technician Decision-Making

Science.gov (United States)

Norcross, Robert

Aircraft maintenance technician decision-making and actions have resulted in aircraft system errors causing aircraft incidents and accidents. Aircraft accident investigators and researchers examined the factors that influence aircraft maintenance technician errors and categorized the types of errors in an attempt to prevent similar occurrences. New aircraft technology introduced to improve aviation safety and efficiency incur failures that have no information contained in the aircraft maintenance manuals. According to the Federal Aviation Administration, aircraft maintenance technicians must use only approved aircraft maintenance documents to repair, modify, and service aircraft. This qualitative research used a grounded theory approach to explore the decision-making processes and actions taken by aircraft maintenance technicians when confronted with an aircraft problem not contained in the aircraft maintenance manuals. The target population for the research was Federal Aviation Administration licensed aircraft and power plant mechanics from across the United States. Nonprobability purposeful sampling was used to obtain aircraft maintenance technicians with the experience sought in the study problem. The sample population recruitment yielded 19 participants for eight focus group sessions to obtain opinions, perceptions, and experiences related to the study problem. All data collected was entered into the Atlas ti qualitative analysis software. The emergence of Aircraft Maintenance Technician decision-making themes regarding Aircraft Maintenance Manual content, Aircraft Maintenance Technician experience, and legal implications of not following Aircraft Maintenance Manuals surfaced. Conclusions from this study suggest Aircraft Maintenance Technician decision-making were influenced by experience, gaps in the Aircraft Maintenance Manuals, reliance on others, realizing the impact of decisions concerning aircraft airworthiness, management pressures, and legal concerns

Time since injury limits but does not prevent improvement and maintenance of gains in balance in chronic stroke.

Science.gov (United States)

Llorens, Roberto; Noé, Enrique; Alcañiz, Mariano; Deutsch, Judith E

2018-01-01

To determine the influence of time since injury on the efficacy and maintenance of gains of rehabilitation of balance after stroke. Forty-seven participants were assigned to a least (6-12 months), a moderate (12-24 months), or a most chronic (>24 months) group. Participants trained for 20 one-hour sessions, administered three to five times a week, combining conventional physical therapy and visual feedback-based exercises that trained the ankle and hip strategies. Participants were assessed before, after the intervention, and one month later with a posturography test (Sway Speed and Limits of Stability) and clinical scales. In contrast to other subjects, the most chronic participants failed to improve their sway and to maintain the benefits detected in the Limits of Stability after the intervention. Although all the participants improved in those clinical tests that better matched the trained skills, time since injury limited the improvement, and over all, the maintenance of gains. Time since injury limits but does not prevent improvement in chronic stages post-stroke, and this effect appears to be more pronounced with maintaining gains. These findings support that training duration and intensity as well as type of therapy may need to be adjusted based on time post-stroke.

Jointly Production and Correlated Maintenance Optimization for Parallel Leased Machines

Directory of Open Access Journals (Sweden)

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.

Are green building features safe for preventive maintenance workers? Examining the evidence.

Science.gov (United States)

Omar, Mohamed Shamun; Quinn, Margaret M; Buchholz, Bryan; Geiser, Ken

2013-04-01

Many newly constructed green buildings (GB) are certified using the United States Green Building Council (USGBC) Leadership in Energy and Environmental Design (LEED) rating system for new construction and major renovation which focuses on architectural and mechanical design to conserve energy, reduce environmental harm, and enhance indoor quality for occupants. This study evaluated the preventive maintenance (PM) worker occupational safety and health (OSH) risks related to the design of GB. PM job hazard analyses (JHA) were performed on the tasks required to operate and maintain five GB features selected from 13 LEED certified GB. A 22-item JHA and OSH risk scoring system were developed. Potentially serious OSH hazards included: green roofs made of slippery material without fall protection; energy recovery wheels and storm water harvesting systems in confined spaces; skylights without guard rails; and tight geothermal well mechanical rooms constraining safe preventive practices. GB can present PM OSH risks and these should be eliminated in the building design phase. Copyright © 2013 Wiley Periodicals, Inc.

Laser application maintenance technologies for nuclear power plant

International Nuclear Information System (INIS)

Shima, Seishi; Sato, Kenji; Kobayashi, Masahiro; Sano, Yuji; Kimura, Seiichiro

2000-01-01

Several plants that were the first to be constructed in Japan have been operating for more than 20 years now, and preventive maintenance is therefore a matter of great importance. This paper summarizes the status of applied laser maintenance technologies both preventive and repair. Especially for the laser peening and laser de-sensitization treatment technology, field applications were also described in detail. In future, expansion of field application area on the preventive maintenance, repair and inspection technologies will be developed. (author)

Collaborative learning in condition based maintenance

NARCIS (Netherlands)

Koochaki, J.; Ao, SI; Gelman, L; Hukins, DWL; Hunter, A; Korsunsky, AM

2009-01-01

In recent years, the importance of reliable and consistent production equipments has increased. As a result, companies are shifting their maintenance policy from preventive maintenance towards Condition Based Maintenance (CBM). Despite the growing trend in this area and success stories of CBM

Take Steps to Prevent Type 2 Diabetes

Science.gov (United States)

... En español Take Steps to Prevent Type 2 Diabetes Browse Sections The Basics Overview Types of Diabetes ... 1 of 9 sections The Basics: Types of Diabetes What is diabetes? Diabetes means you have glucose ( ...

Ageing Management Based Maintenance at ETRR-II

Energy Technology Data Exchange (ETDEWEB)

Kamoon, A.; Ali, A., E-mail: akamoun2004@yahoo.com [Inshas Nuclear Research Centre, Egyptian Atomic Energy Authority (EAEA), Cairo (Egypt)

2014-08-15

The second research reactor of Egypt, ETRR-II, is an open pool type multi-purpose reactor of 22 MW that has been in operation since 1998. The main purposes of ETRR-II are the production of radioisotopes, personnel training, research and development. Ageing management of ETRR-II is based on the maintenance programme. This programme was planned to have a proactive maintenance strategy that mainly depends on adequate preventive and predictive maintenance. Screening of SSCs is based on safety classes, needs and quality levels. The operation condition and maintenance history are the basis to assess the level of degradation. The ultimate aim of the maintenance team is to perform adequate maintenance work only when it is really necessary. The objectives of the ageing management based maintenance are to maintain and improve equipment availability, confirm compliance with operational limits and conditions, and detect and correct any abnormal condition that might affect reactor safety. The programme also helps to detect trends in ageing so that a plan for mitigating ageing effects can be prepared and implemented. Reactor service conditions are monitored through many parameters and conditions such as conductivity and pH of coolant water, water radiochemical analysis, thermal and hydraulic parameters, a leak detection system, corrosion rate of piping, vibration level of rotating equipment and control rod drop time.

Airline experience with reliability-centered maintenance

International Nuclear Information System (INIS)

Matteson, T.D.

1985-01-01

Reliability-Centered Maintenance is a process for developing preventive maintenance programs. Its concepts evolved from the post WWII experience of the airline community. Its genesis was in a paper by F. Stanley Nowlan and Thomas D. Matteson of United Airlines for the American Institute of Aeronautics and Astronautics in 1967. Its first application was to the Boeing 747. It has subsequently been adopted by the FAA and the Department of Defense and applied to many new transport and military aircraft. Its objective is applicable and effective preventive maintenance and it has proven to be a highly effective replacement for the prior intuitive processes for selective preventive maintenance tasks. It focuses on system functions, functional failures, then dominant failure modes and effects. It then uses a decision tree to classify failure criticality and identify applicable and effective tasks. The result is a program focused on maintaining inherent safety and reliability at minimum cost. (orig.)

Airline experience with reliability-centered maintenance

Energy Technology Data Exchange (ETDEWEB)

Matteson, T.D.

1985-11-01

Reliability-Centered Maintenance is a process for developing preventive maintenance programs. Its concepts evolved from the post WWII experience of the airline community. Its genesis was in a paper by F. Stanley Nowlan and Thomas D. Matteson of United Airlines for the American Institute of Aeronautics and Astronautics in 1967. Its first application was to the Boeing 747. It has subsequently been adopted by the FAA and the Department of Defense and applied to many new transport and military aircraft. Its objective is applicable and effective preventive maintenance and it has proven to be a highly effective replacement for the prior intuitive processes for selective preventive maintenance tasks. It focuses on system functions, functional failures, then dominant failure modes and effects. It then uses a decision tree to classify failure criticality and identify applicable and effective tasks. The result is a program focused on maintaining inherent safety and reliability at minimum cost. (orig.).

Let's prevent diabetes

DEFF Research Database (Denmark)

Gray, Laura J.; Khunti, Kamlesh; Williams, Sian

2012-01-01

Background: The prevention of type 2 diabetes is a globally recognised health care priority, but there is a lack of rigorous research investigating optimal methods of translating diabetes prevention programmes, based on the promotion of a healthy lifestyle, into routine primary care. The aim...... of the study is to establish whether a pragmatic structured education programme targeting lifestyle and behaviour change in conjunction with motivational maintenance via the telephone can reduce the incidence of type 2 diabetes in people with impaired glucose regulation (a composite of impaired glucose...... of type 2 diabetes. Secondary outcomes include changes in HbA1c, blood glucose levels, cardiovascular risk, the presence of the Metabolic Syndrome and the cost-effectiveness of the intervention.Methods: The study consists of screening and intervention phases within 44 general practices coordinated from...

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

International Nuclear Information System (INIS)

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.

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

Energy Technology Data Exchange (ETDEWEB)

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.

Maintenance Policy in Public-Transport Involving Government Subsidy

Science.gov (United States)

Pasaribu, U. S.; Bayuzetra, Y.; Gunawan, L. E.; Husniah, H.

2018-02-01

A public transport with government subsidy is considered to encourage the sustainability of the transportation. The transportations revenue is determined by the maximum of the uptimes of the vehicle. In this paper, we study a one-dimensional maintenance policy for new vehicle which is characterized by age parameter. We consider that the degradation of the vehicle is affected by the age of the vehicle, and modelled by using a one-dimensional approach. The owner performs both preventive and corrective maintenance actions, and the preventive maintenance action will reduce the vehicle failure rate and hence it will decrease the corrective maintenance cost during the life time of the vehicle. The decision problem for the owner is to find the optimal preventive maintenance time of the vehicle of each subsidy option offered by maximizing the expected profit for each subsidy.

Reliability centred maintenance of nuclear power plant facilities

International Nuclear Information System (INIS)

Kovacs, Zoltan; Novakova, Helena; Hlavac, Pavol; Janicek, Frantisek

2011-01-01

A method for the optimization of preventive maintenance nuclear power plant equipment, i.e. reliability centred maintenance, is described. The method enables procedures and procedure schedules to be defined such as allow the maintenance cost to be minimized without compromising operational safety or reliability. Also, combinations of facilities which remain available and ensure reliable operation of the reactor unit during the maintenance of other pieces of equipment are identified. The condition-based maintenance concept is used in this process, thereby preventing unnecessary operator interventions into the equipment, which are often associated with human errors. Where probabilistic safety assessment is available, the most important structures, systems and components with the highest maintenance priority can be identified. (orig.)

Random maintenance policies

CERN Document Server

Nakagawa, Toshio

2014-01-01

Exploring random maintenance models, this book provides an introduction to the implementation of random maintenance, and it is one of the first books to be written on this subject.  It aims to help readers learn new techniques for applying random policies to actual reliability models, and it provides new theoretical analyses of various models including classical replacement, preventive maintenance and inspection policies. These policies are applied to scheduling problems, backup policies of database systems, maintenance policies of cumulative damage models, and reliability of random redundant systems. Reliability theory is a major concern for engineers and managers, and in light of Japan’s recent earthquake, the reliability of large-scale systems has increased in importance. This also highlights the need for a new notion of maintenance and reliability theory, and how this can practically be applied to systems. Providing an essential guide for engineers and managers specializing in reliability maintenance a...

Installation, maintenance and operating manual for the Lucas-type fuel injection system of the 3 B rotary engine

Science.gov (United States)

1985-01-01

The installation procedure, maintenance, adjustment and operation of a Lucas type fuel injection system for 13B rotary racing engine is outlined. Components of the fuel injection system and installation procedure and notes are described. Maintenance, adjustment, and operation are discussed.

A development of maintenance educational support method by using navigation method Pt. 4. A development of a paper prototype system for the RHR pump maintenance educational support

International Nuclear Information System (INIS)

Yoshino, Kenji; Hirotsu, Yuko; Fujimoto, Junzo; Tsumura, Joji

2004-01-01

This research establishes the new maintenance educational support prototype system for aiming at organization as Trinity (a supervision person, a construction person in charge, a work person in charge, and group length), and improvement in human reliability for the purpose of aiming at before hand prevention of a systematic error, human error, and the accident and a trouble. (1) This maintenance educational support: system made educational start to the educational end the structure navigated exactly, carrying out the exchange with a data base along with the road map which divided action (act) of the work process and worker concerning RHR pump maintenance work for a participant etc. by class. (2) First, according to a participant's attribute, this educational support system performs educational support (a question and reply) concerning an organization and organization, and judges knowledge and a nature type based on the result. Furthermore, educational support (a question and reply) concerning maintenance work is performed, and a knowledge level is judged based on the result. And it considered as the structure which performs the comprehensive judgment about an organization, organization, and the educational effect concerning maintenance work at the last. (3) The judgment pattern of the knowledge and nature after the educational support end concerning a participant's organization and organization was made into four kinds which consist of (1) organization priority and duty A type, (2) organization priority and an adaptable type, (3) individual priority and an adaptable type, and (4) individual priority and a duty priority type. (4) The judgment pattern of the knowledge level after the educational support end concerning maintenance work of a participant was used as three kinds of evaluation axes, schedule management, apparatus reliability capability, and human-being reliability. (author)

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

International Nuclear Information System (INIS)

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)

Plant inspection and maintenance technology

International Nuclear Information System (INIS)

Miyahara, Masatoshi; Kanazawa, Masafumi

1995-01-01

The article reports on information systems and related tools that support routine inspection and preventive maintenance activities, which contribute to safer plant operation and increase plant operating duty. Tools include the Mitsubishi Electric Reliability and Availability Upgrade Program-Nuclear (MELRAP-N), which supports the general evolution of industry operating experiences, periodic component replacement management, management of discontinued and modified components, periodic inspection item management, and periodic inspection workplace management. The article also introduces a comprehensive preventive maintenance management system currently under development. (author)

Concepts for measuring maintenance performance and methods for analysing competing failure modes

International Nuclear Information System (INIS)

Cooke, Roger; Paulsen, Jette

1997-01-01

Measurement of maintenance performance is done on the basis of component history data in which service sojourns are distinguished according to whether they terminate in corrective or preventive maintenance. From the viewpoint of data analysis, corrective and preventive maintenance constitute competing failure nudes. This article examines ways to assess maintenance performance without introducing statistical assumptions, then introduces a plausible statistical model for describing the interaction of preventive and corrective maintenance, and finally illustrates these with examples from the Nordic TUD data system

Maintenance erlotinib in advanced nonsmall cell lung cancer: cost-effectiveness in EGFR wild-type across Europe

Directory of Open Access Journals (Sweden)

Walleser S

2012-09-01

Full Text Available Silke Walleser,1 Joshua Ray,2 Helge Bischoff,3 Alain Vergnenègre,4 Hubertus Rosery,5 Christos Chouaid,6 David Heigener,7 Javier de Castro Carpeño,8 Marcello Tiseo,9 Stefan Walzer21Health Economic Consultancy, Renens, Switzerland; 2F Hoffmann-La Roche Pharmaceuticals AG, Basel, Switzerland; 3Thoracic Hospital of Heidelberg, Heidelberg, Germany; 4Limoges University Hospital, Limoges, France; 5Assessment-in-Medicine GmbH, Loerrach, Germany; 6Hospital Saint Antoine, Paris, France; 7Hospital Grosshansdorf, Grosshansdorf, Germany; 8University Hospital La Paz, Madrid, Spain; 9University Hospital of Parma, Parma, ItalyBackground: First-line maintenance erlotinib in patients with locally advanced or metastatic nonsmall cell lung cancer (NSCLC has demonstrated significant overall survival and progression-free survival benefits compared with best supportive care plus placebo, irrespective of epidermal growth factor receptor (EGFR status (SATURN trial. The cost-effectiveness of first-line maintenance erlotinib in the overall SATURN population has been assessed and published recently, but analyses according to EGFR mutation status have not been performed yet, which was the rationale for assessing the cost-effectiveness of first-line maintenance erlotinib specifically in EGFR wild-type metastatic NSCLC.Methods: The incremental cost per life-year gained of first-line maintenance erlotinib compared with best supportive care in patients with EGFR wild-type stable metastatic NSCLC was assessed for five European countries (the United Kingdom, Germany, France, Spain, and Italy with an area-under-the-curve model consisting of three health states (progression-free survival, progressive disease, death. Log-logistic survival functions were fitted to Phase III patient-level data (SATURN to model progression-free survival and overall survival. The first-line maintenance erlotinib therapy cost (modeled for time to treatment cessation, medication cost in later lines, and

A production model and maintenance planning model for the process industry

NARCIS (Netherlands)

Ashayeri, J.; Teelen, A.; Selen, W.J.

1995-01-01

In this paper a model is developed to simultaneously plan preventive maintenance and production in a process industry environment, where maintenance planning is extremely important. The model schedules production jobs and preventive maintenance jobs, while minimizing costs associated with

Effect of Maintenance Therapy with Isoxsuprine in the Prevention of Preterm Labor: Randomized controlled trial

Science.gov (United States)

Alavi, Azin; Rajaee, Minoo; Amirian, Malihe; Mahboobi, Hamidreza; Jahanshahi, Keramat Allah; Faghihi, Armaghan

2015-01-01

Background: Isoxsuprine (Vasodilan) is a beta-adrenergic that directly affects the vascular smooth muscle and results in peripheral vascular dilation. Isoxsuprine relaxes the uterine smooth muscles and is used for treatment of pre-term labor and dysmenorrhea. Isoxsuprine is used extensively in hospitals and private clinics in Iran; however, few studies have reported its safety and efficacy in the prevention of pre-term labor. Objective: The aim of this study was to assess the effect of maintenance therapy with oral isoxsuprine for the prevention of pre-term labor. Methods: We undertook a blinded prospective randomized trial of 70 women with singleton pregnancies who presented in pre-term labor between 26 to 34 weeks of gestation. After arresting the contractions with intravenous magnesium sulfate, the patients were randomized into two groups, with the treatment group receiving oral isoxsuprine until 34 weeks of gestation. Response to treatment was assessed by the progression of the pregnancies in both groups. The data were analyzed using SPSS software. Results: Our results showed that 14 (40%) of the patients in the case group and 12 (34.29%) of patients in the control group had pre-term births, and there was no significant difference between the two groups (P=0.621). Also four women (11.43%) in the case group and five women (14.29%) in the control group delivered before 34 weeks (P=0.721). Conclusion: Oral isoxsuprine was not effective as a maintenance treatment in preventing pre-term births or in delaying delivery until after 34 weeks. Larger studies are needed to identify the best treatment for pre-term labor. PMID:26396726

Balancing preventive and corrective maintenance in Cernavoda Unit 1 NPP

International Nuclear Information System (INIS)

Riedel, M.; Marinescu, S.

2000-01-01

The paper presents a short reminder of Romania's Cernavoda NPP entering commercial operation and a brief description of the CANDU-6 project on which Unit 1 is based. The short term objectives of the maintenance management, the status of the existing maintenance programmes as well as future predictable maintenance programmes are outlined together with the Government plan to complete the balance of NPP. (author)

Type 1 diabetes: New horizons in prediction and prevention.

Science.gov (United States)

Razack, Natasha N; Wherrett, Diane K

2005-01-01

Significant advances have been made in our understanding of the pathogenesis of type 1 diabetes and our ability to predict risk for the condition. This knowledge is being used to develop new and innovative strategies to prevent type 1 diabetes or to prevent further destruction of beta cells in those who are newly diagnosed. Several multicentre studies are underway investigating the natural history of the disease, the genetics behind the disease and ways to stop the autoimmune reaction against beta cells (Type 1 Diabetes TrialNet, Type 1 Diabetes Genetics Consortium and the Trial to Reduce Diabetes in the Genetically at Risk [TRIGR] Study Group). The stage is set to find an agent or strategy to prevent type 1 diabetes or to preserve the residual beta cell mass in new-onset patients.

Machine Maintenance Scheduling with Reliability Engineering Method and Maintenance Value Stream Mapping

Science.gov (United States)

Sembiring, N.; Nasution, A. H.

2018-02-01

Corrective maintenance i.e replacing or repairing the machine component after machine break down always done in a manufacturing company. It causes the production process must be stopped. Production time will decrease due to the maintenance team must replace or repair the damage machine component. This paper proposes a preventive maintenance’s schedule for a critical component of a critical machine of an crude palm oil and kernel company due to increase maintenance efficiency. The Reliability Engineering & Maintenance Value Stream Mapping is used as a method and a tool to analize the reliability of the component and reduce the wastage in any process by segregating value added and non value added activities.

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

OpenAIRE

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...

CANDU plant maintenance: Recent developments

International Nuclear Information System (INIS)

Charlebois, P.

2000-01-01

CANDU units have long been recognized for their exceptional safety and reliability. Continuing development in the maintenance area has played a key role in achieving this performance level. For over two decades, safety system availability has been monitored closely and system maintenance programs adjusted accordingly to maintain high levels of performance. But as the plants approach mid life in a more competitive environment and component aging becomes a concern, new methods and techniques are necessary. As a result, recent developments are moving the maintenance program largely from a corrective and preventive approach to predictive and condition based maintenance. The application of these techniques is also being extended to safety related systems. These recent developments include use of reliability centred methods to define system maintenance requirements and strategies. This approach has been implemented on a number of systems at Canadian CANDU plants with positive results. The pilot projects demonstrated that the overall maintenance effort remained relatively constant while the system performance improved. It was also possible to schedule some of the redundant component maintenance during plant operation without adverse impact on system availability. The probabilistic safety assessment was found to be useful in determining the safety implications of component outages. These new maintenance strategies are now making use of predictive and condition based maintenance techniques to anticipate equipment breakdown and schedule preventive maintenance as the need arises rather than time based. Some of these techniques include valve diagnostics, vibration monitoring, oil analysis, thermography. Of course, these tools and techniques must form part of an overall maintenance management system to ensure that maintenance becomes a living program. To facilitate this process and contain costs, new information technology tools are being introduced to provide system engineers

Comparative evaluation of maintenance performance using subsurvival functions

DEFF Research Database (Denmark)

Paulsen, J.L.; Cooke, R.; Nyman, R.

1997-01-01

Subsurvival functions are applied to operational data for the control rod drive systems of Nordic nuclear reactors to evaluate maintenance performance. Competing failure modes are preventive and corrective maintenance. Maintenance indicators are defined and evaluated for 8 plants. (C) 1997 Elsevier...

Organization and mechanization of maintenance operations at NPPs with the WWER type reactors

International Nuclear Information System (INIS)

Titov, A.A.

1983-01-01

The structure of capital investments defining organization and mechanization of maintepance operations at NPPs with the WWER type reactors is analyzed. The trends in development of optimum decisions for organization and mechanization of repair obs at NPPs being designed taking into account the prospects of nuclear powep enginerning development, the system of NPP maintenance servicing, as well as the structure of repair-productive capacities are discussed. On the basis of the analysis of the data obtained in designing the Zaporozhskaya NPP it is shown that the capital investments for organizing and mechanization of maintenance operations at the unified NPP site with four WWER-1000 reactors reach nearly 18 roubles/kW. A conclusion is drawn that at present the design of an NPP with the WWER-1000 reactor totally meets the requirements of realization of periodic maintenance operations. It is advisable to cooperate the NPP management with that of a thermal power station from the viewpoint of using manpower, which would improve the operating conditions and labour productivity of workers engaged in repair and, consequently, reduce the capital investments and repair expenditures

Human factor analysis and preventive countermeasures of maintenance in nuclear power plant

International Nuclear Information System (INIS)

Zhang Li; Hu Chao

2008-01-01

Based on the human error analysis theory and the characteristics of maintenance in a nuclear power plant, human factors of maintenance in NPP are divided into three different areas: human, technology, and organization, in which human refers to the individual factors, mainly including psychological quality, physiological characteristic, state of health, knowledge, skill level, and interpersonal relationship. Technology includes the maintenance technology, maintenance strategy, maintenance tool, maintenance interface, maintenance regulation, and work environment. Organization includes task arrangement, information communication, training, personnel external environment, team construction, and leadership. The analysis also reveals that the organization factors, which can indirectly influence personnel performance, are the primary initiators of human error. Based on these, some countermeasures are brought forward in order to reduce human errors. (authors)

Maintenance Planning for Historic Buildings

Directory of Open Access Journals (Sweden)

Diana Plian

2008-01-01

Full Text Available The key to good maintenance of historic buildings is a long-range maintenance plan. Long-range planning recognizes a responsibility to the future to prolong the useful life of a building by preserving it in its present condition and preventing or slowing deterioration and damage from natural or other causes.

Maintenance-Ready Web Application Development

Directory of Open Access Journals (Sweden)

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.

40 CFR 68.56 - Maintenance.

Science.gov (United States)

2010-07-01

... Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CHEMICAL ACCIDENT PREVENTION PROVISIONS Program 2 Prevention Program § 68.56 Maintenance. (a) The owner or operator shall prepare and implement procedures to maintain the on-going mechanical integrity of the process...

Development of plant maintenance systems

International Nuclear Information System (INIS)

Tomita, Jinji; Ike, Masae; Nakayama, Kenji; Kato, Hisatomo

1989-01-01

Toshiba is making active efforts for the continuing improvement of reliability and maintainability of operating nuclear power plants. As a part of these efforts, the company has developed new maintenance administration systems, diagnostic monitoring facilities for plant equipments, computer-aided expert systems, and remote-controlled machines for maintenance work. The maintenance administration systems provide efficient work plans and data acquisition capabilities for the management of personnel and equipments involved in nuclear power plant maintenance. The plant diagnostic facilities monitor and diagnose plant conditions for preventive maintenance, as well as enabling rapid countermeasures to be carried out should they be required. Expert systems utilizing artificial intelligence (AI) technology are also employed. The newly developed remote-controlled machines are useful tools for the maintenance inspection of equipment which can not be easily accessed. (author)

Probabilistic approach to rationalization of plants maintenance

International Nuclear Information System (INIS)

Kasai, Masao; Notoya, Junichi; Uchimoto, Tetsuya; Miya, Kenzo

2001-01-01

Since there are a lot of equipments in large plants, their safety and reliability cannot be kept as high level as designed without maintenance activities. Then preventive maintenance is intensively executed in some large plants. However, it will be inefficient to perform the preventive maintenance blindly. To make maintenance activities effective, it is essential to identify the critical equipments influencing plant safety and/or reliability and carry out the maintenance by focusing attentions on these equipments. It needs quantitative analyses to identify the critical equipments based on the data of failure rates. However, complete data set of failure rates cannot necessarily be available for some plants such as nuclear power plants. In this study, we carry out the reliability analysis for generic LNG plant and calculate various quantitative risk importance measures for each equipment. We propose rather qualitative representations for some quantitative measures, considering the situation without complete data set and conclude that it is possible to rationalize maintenance procedure by using these rather qualitative measures, though the level of rationalization is of course limited. (author)

Inspection, evaluation and maintenance guidelines for reactor vessel internals in JAPAN

International Nuclear Information System (INIS)

Sakashita, Akihiro; Goto, Tomoya; Hirano, Shinro; Dozaki, Koji

2010-01-01

Inspection and Evaluation Guidelines for reactor internals has been taken into the Rules on Fitness-for–Service for Nuclear Power Plants of The Japan Society of Mechanical Engineers. It is a base of the maintenance plan of each Nuclear Power Plant. A plant maintenance methodology will have more importance to maintain the plant safety and stable plant operation. This paper introduces the systematization of the maintenance such as repair, replacement, preventive maintenance in these guidelines. Maintenance methodologies are classified follows. Repair: methodology to reinforce degraded parts by some methods or prevent progress of degradation of without replacement of the existing structure when the degradation of structure is actualized. Replacement: methodology to replace the existing structure with new one when the degradation of structure is actualized. Preventive maintenance : methodology to mitigate the damaged condition. When the maintenance methodologies are implemented in the actual plant, we have to consider the feedback of the inspection program and plant life management. (author)

Costs of Development and Maintenance of an Internet Program for Teens with Type 1 Diabetes

Science.gov (United States)

Grey, Margaret; Liberti, Lauren; Whittemore, Robin

2015-01-01

Many adolescents with type 1 diabetes (T1D) have difficulty completing self-management tasks within the context of their social environments. Group-based approaches to psycho-educational support have been shown to prevent declines in glucose control, but are challenging to implement due to youths’ many activities and costs. A novel solution is providing psycho-educational support via the internet. The purpose of this study is to describe the cost of developing and maintaining two internet psycho-educational programs, both of which have been shown to improve health outcomes in adolescents with T1D. We calculated actual costs of personnel and programming in the development of TEENCOPE™ and Managing Diabetes, two highly interactive programs that were evaluated in a multi-site clinical trial (n=320). Cost calculations were set at U.S. dollars and converted to value for 2013 as expenses were incurred over 6 years. Development costs over 1.5 years totaled $324,609, with the majority of costs being for personnel to develop and write content in a creative and engaging format, to get feedback from teens on content and a prototype, and IT programming. Maintenance of the program, including IT support, a part-time moderator to assure safety of the discussion board (0.5–1 hour/week), and yearly update of content was $43,845/year, or $137.00 per youth over 4.5 years. Overall, program and site development were relatively expensive, but the program reach was high, including non-white youth from 4 geographically distinct regions. Once developed, maintenance was minimal. With greater dissemination, cost-per-youth would decrease markedly, beginning to offset the high development expense. PMID:26213677

Maintenance optimization after RCM

International Nuclear Information System (INIS)

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)

The impact of preventive maintenance practices on manufacturing performance: A proposed model for SMEs in Malaysia

Science.gov (United States)

Lazim, Halim Mad; Taib, Che Azlan; Lamsali, Hendrik; Saleh, Mohamed Najib; Subramaniam, Chandrakantan

2016-08-01

Preventive maintenance (PM) plays important role to avoid or mitigate potential stoppages and disruptions of equipment or machinery from occurring in daily operations. PM emphasized total employee involvement and it is important for companies as well as Small and Medium Sized Enterprises (SMEs). SME sectors contribution to the Malaysian economy makes up 95% of the total manufacturers, however PM remain relatively lacking. The ability, reliability and effective maintenance management is highly important in order to achieve desired manufacturing performance. Therefore, organizational capability in planning, controlling, implementing and monitoring PM activities is important. Furthermore, empirical evidence on the potential impact of PM practices towards manufacturing performance with organizational capability as a moderating effect is still limited and indecisive. Henceforth, this paper aims to explore and investigate potential relationships between PM practices and manufacturing performance moderated by organizational capability in the contact of Malaysian SMEs in the manufacturing sector. Correspondently, the study intends to propose a new research framework and hypotheses to examine the abovementioned relationships. The proposed framework includes PM team, PM strategy and planned maintenance as the determinants, while organizational capability serves as the moderating variable. Manufacturing performance will be viewed in terms of innovation and financial factors. Proposed research direction and conclusion are discussed at the end of the study.

AIRCRAFT MAINTENANCE HANGAR

Directory of Open Access Journals (Sweden)

GEAMBASU Gabriel George

2017-05-01

Full Text Available The paper presents the maintenance process that is done on an airplane, at a certain period of time, or after a number of flight hours or cycles and describes the checks performed behind each inspection. The first part of research describes the aircraft maintenance process that has to be done after an updated maintenance manual according with aircraft type, followed by a short introduction about maintenance hangar. The second part of the paper presents a hangar design with a foldable roof and walls, which can be folded or extended, over an airplane when a maintenance process is done, or depending on weather condition.

Preventive and Predictive Maintenance, Warehousing of Spares, Periodic Testing and In-Service Inspection Activities at the Nigerian Research Reactor-1 Facility

Energy Technology Data Exchange (ETDEWEB)

Yusuf, I.; Mati, A. A.; Dewu, B. B.M., [Centre for Energy Research and Training, Ahmadu Bello University, Zaria (Nigeria)

2014-08-15

The Nigerian Research Reactor–1, or NIRR-1, is sited at Centre for Energy Research and Training, Ahmadu Bello University, Zaria, Nigeria. Activities on preventive or routine maintenance have been institutionalized since the commissioning of the reactor in February 2004. This has grossly reduced the rates of corrective maintenance activities and helped the reactor management a great deal in predicting failure rates of reactor components and other auxiliary units. Routine maintenance of systems and components are being carried out on a weekly, quarterly and annual basis based on manufacturer’s recommendations, which have been reviewed and improved over the years. The paper presents the implementation of maintenance activities in NIRR-1 from its initial criticality in 2004 till today and the new scheme for periodic testing and in-service-inspection developed after an IAEA Integrated Safety Assessment of Research Reactors mission. The measures put in place are envisaged to reduce the negative impact of ageing on NIRR-1 and its auxiliary systems. (author)

Proceedings of the fourth international conference on CANDU maintenance

International Nuclear Information System (INIS)

1997-01-01

These proceedings record the information presented at the 4th International Conference on CANDU Maintenance held November 16-18,1997 in Toronto, Canada. The papers for these proceedings were prepared on component maintenance, human performance, steam generator leak detection, fuel channel inspections, rotating equipment maintenance, surveillance programs, inspection techniques, valve maintenance, steam generator repairs and performance, reactor aging management and preventative maintenance

Proceedings of the fourth international conference on CANDU maintenance

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-07-01

These proceedings record the information presented at the 4th International Conference on CANDU Maintenance held November 16-18,1997 in Toronto, Canada. The papers for these proceedings were prepared on component maintenance, human performance, steam generator leak detection, fuel channel inspections, rotating equipment maintenance, surveillance programs, inspection techniques, valve maintenance, steam generator repairs and performance, reactor aging management and preventative maintenance.

Risk-Based Operation and Maintenance of Offshore Wind Turbines

DEFF Research Database (Denmark)

Nielsen, Jannie Sønderkær

For offshore wind turbines, maintenance costs are substantial due to a large number of component failures. In addition to the repair costs, equipment costs and lost production costs are large due to limited accessibility to the turbines. In order to reduce the costs, preventive methods can be used......, but presently maintenance is not planned using advanced methods taking all available information into account in a consistent manner. Maintenance decisions can be made based on risk-based methods, where the total expected life cycle costs are minimized. Methods have been developed for assessing the corrective...... maintenance costs, and many studies have also been published for preventive maintenance. However, an important part is the modeling of the relationship between maintenance and reliability, which is typically not modeled in a consistent way. Therefore, the methods cannot be used directly for optimal...

A proactive condition-based maintenance strategy with both perfect and imperfect maintenance actions

International Nuclear Information System (INIS)

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

Multi-level predictive maintenance for multi-component systems

International Nuclear Information System (INIS)

Nguyen, Kim-Anh; Do, Phuc; Grall, Antoine

2015-01-01

In this paper, a novel predictive maintenance policy with multi-level decision-making is proposed for multi-component system with complex structure. The main idea is to propose a decision-making process considered on two levels: system level and component one. The goal of the decision rules at the system level is to address if preventive maintenance actions are needed regarding the predictive reliability of the system. At component level the decision rules aim at identifying optimally a group of several components to be preventively maintained when preventive maintenance is trigged due to the system level decision. Selecting optimal components is based on a cost-based group improvement factor taking into account the predictive reliability of the components, the economic dependencies as well as the location of the components in the system. Moreover, a cost model is developed to find the optimal maintenance decision variables. A 14-component system is finally introduced to illustrate the use and the performance of the proposed predictive maintenance policy. Different sensitivity analysis are also investigated and discussed. Indeed, the proposed policy provides more flexibility in maintenance decision-making for complex structure systems, hence leading to significant profits in terms of maintenance cost when compared with existing policies. - Highlights: • A predictive maintenance policy for complex structure systems is proposed. • Multi-level decision process based on prognostic results is proposed. • A cost-based group importance measure is introduced for decision-making. • Both positive and negative dependencies between components are investigated. • A cost model and Monte Carlo simulation are developed for optimization process.

A preventive maintenance model with a two-level inspection policy based on a three-stage failure process

International Nuclear Information System (INIS)

Wang, Wenbin; Zhao, Fei; Peng, Rui

2014-01-01

Inspection is always an important preventive maintenance (PM) activity and can have different depths and cover all or part of plant systems. This paper introduces a two-level inspection policy model for a single component plant system based on a three-stage failure process. Such a failure process divides the system′s life into three stages: good, minor defective and severe defective stages. The first level of inspection, the minor inspection, can only identify the minor defective stage with a certain probability, but can always reveal the severe defective stage. The major inspection can however identify both defective stages perfectly. Once the system is found to be in the minor defective stage, a shortened inspection interval is adopted. If however the system is found to be in the severe defective stage, we may delay the maintenance action if the time to the next planned PM window is less than a threshold level, but otherwise, replace immediately. This corresponds to the well adopted maintenance policy in practice such as periodic inspections with planned PMs. A numerical example is presented to demonstrate the proposed model by comparing with other models. - Highlights: • The system′s deterioration goes through a three-stage process, namely, normal, minor defective and severe defective. • Two levels of inspections are proposed, e.g., minor and major inspections. • Once the minor defective stage is found, instead of taking a maintenance action, a shortened inspection interval is recommended. • When the severe defective stage is found, we delay the maintenance according to the threshold to the next PM. • The decision variables are the inspection intervals and the threshold to PM

Application of reliability centered maintenance to Embalse NPP

International Nuclear Information System (INIS)

Torres, Antonio; Perdomo, Manuel; Fornero, Damian; Corchera, Roberto

2010-01-01

One of the most recent applications of Probabilistic Safety Analysis to Embalse NPP is the Safety Oriented Maintenance Program developed through the Reliability Centered Maintenance (RCM) methodology. Such an application was carried out by a cooperated effort between the staff of nuclear safety department of NPP and experts from Instituto Superior de Tecnologias y Ciencias Aplicadas of Cuba. So far 6 technological systems have been analyzed with important results regarding the optimization of preventive and predictive maintenance program of those systems. Any tasks of RCM were automated via MOSEG code. The results of this study were focused on the elaboration and modification of the Preventive Program, prioritization of stocks, reorientation of predictive techniques and modification in the time parameters of maintenance. (author)

Asphalt in Pavement Maintenance.

Science.gov (United States)

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…

Gentilly 2 maintenance in a total quality environment

Energy Technology Data Exchange (ETDEWEB)

Ross, M H; Marois, H [Hydro-Quebec, Gentilly (Canada). Gentilly Generating Station

1993-12-31

Comprehensive preventive maintenance programs at Gentilly-2 Nuclear Generating Station are based on a policy that seeks to balance requirements against resources. A commitment to total quality aims at performance improvement and total customer satisfaction. To improve overall performance to an annual availability factor of 90%, planned outages must be limited to 21 days per year, and the preventive maintenance program must be upgraded. A quality improvement team is involved in supporting this initiative. This team will seek to bring a new balance to the program, and eventually optimize it, using reliability-centred maintenance techniques. 24 figs.

Initiating statistical maintenance optimization

International Nuclear Information System (INIS)

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)

Safety related maintenance in the framework of the reliability centered maintenance concept

International Nuclear Information System (INIS)

1992-07-01

Elevated safety requirements and ever increasing costs of maintenance of nuclear power plants stimulate the interest in different methods and approaches to optimize maintenance activities. Among different concepts, the Reliability Centered Maintenance (RCM) as an approach to improve Preventive Maintenance (PM) programmes is being widely discussed an applied in several IAEA Member States. In order to summarize basic principles and current implementation of the RCM, the IAEA organized a Consultants Meeting in November 1990. The report prepared during that meeting was discussed during the Technical Committee Meeting (TCM) held in May 1991. Numerous technical presentations as well as panel and plenary discussions took place at the TCM. This document contains the report of the Consultants Meeting (modified to include comments of the TCM), a summary of the most important discussions as well as all 14 papers presented at the TCM

Some aspects related to the management of maintenance for a TRIGA research reactor In Romania

International Nuclear Information System (INIS)

Vieru, G.

2003-01-01

Safety management for a nuclear research reactor involves 'good dependability management' of operations activities, such as: reliability, availability, maintainability and maintenance support. In order to evaluate the safety management aspects intended to be applied by research reactor management, the performance dependability indicators and their impact on reactor availability and reactor safety have to be established. The document ISO 9000-4/IEC 300-1 'Dependability Management' (1995), describes five internationally agreed indicators of reactor equipment dependability. Each of them can be used for corrective maintenance or for preventive maintenance, such as: I 1 - equipment Maintenance Frequency; I 2 - equipment Maintenance Effort; I 3 - equipment Maintenance Downtime Factor; I 4 - equipment Maintenance Contribution to the System Function Downtime Factor; I 5 - equipment Maintenance Contribution to the reactor Capability Loss Factor. This paper presents an evaluation of those 5 mentioned indicators with reference to the primary circuit of the INR's TRIGA research reactor and conclusion. The analyzed period was between 1994- 1999. It is to be noted that this type of analysis is performed for the first time for a research reactor. (author)

Preventive maintenance basis: Volume 10 -- High voltage electric motors (5 kV and greater). Final report

International Nuclear Information System (INIS)

Worledge, D.; Hinchcliffe, G.

1997-07-01

US nuclear plants are implementing preventive maintenance (PM) tasks with little documented basis beyond fundamental vendor information to support the tasks or their intervals. The Preventive Maintenance Basis project provides utilities with the technical basis for PM tasks and task intervals associated with 40 specific components such as valves, electric motors, pumps, and HVAC equipment. This report provides an overview of the PM Basis project and describes use of the PM Basis database. Volume 10 of the report provides a program of PM tasks suitable for application to high voltage (5kV and greater) electric motors in nuclear power plants. The PM tasks that are recommended provide a cost-effective way to intercept the causes and mechanisms that lead to degradation and failure. They can be used, in conjunction with material from other sources, to develop a complete PM program or to improve an existing program. Users of this information will be utility managers, supervisors, craft technicians, and training instructors responsible for developing, optimizing, or fine-tuning PM programs. Reactor Coolant Pumps motors (RCP's) are not excluded from this report in so far as good PM practices for motors of the appropriate class are concerned. However, the special auxiliary equipment normally associated with RCP's has not been included. Consequently, this report does not provide a complete PM program for RCP's. Industry and vendor programs for RCP's should be consulted for complete definition of RCP motor PM programs

Maintenance of the Hanford cone penetrometer platform during fiscal year 1999

International Nuclear Information System (INIS)

IWATATE, D.F.

1998-01-01

This SOW describes services requested of Applied Research and Associates, Inc. (ARA), as a commercial provider of cone penetrometer equipment and services, to provide routine inspection and minimum preventive maintenance on the Hanford CP Platform (CPP) during Fiscal Year 1999. This SOW specifically pertains to the maintenance of the CPP and associated support equipment and is limited in scope to routine preventive maintenance and identification of any deficiencies. ARA is the original manufacturer of the CPP and will conduct this work following the vendor-prepared maintenance schedule

Photovoltaic power plants maintenance; El mantenimiento en plantas fotovoltaicas

Energy Technology Data Exchange (ETDEWEB)

Suanzes, F.; Rodelgo, I.

2010-07-01

It is reviewed the evolution of the maintenance contracts in solar facilities in a young environment and with a large projection. Thus, is described the preventive maintenance in this kind of facilities, and are also analyzed the most relevant cases of corrective maintenance. (Author)

A hybrid Constraint Programming/Mixed Integer Programming framework for the preventive signaling maintenance crew scheduling problem

DEFF Research Database (Denmark)

Pour, Shahrzad M.; Drake, John H.; Ejlertsen, Lena Secher

2017-01-01

A railway signaling system is a complex and interdependent system which should ensure the safe operation of trains. We introduce and address a mixed integer optimisation model for the preventive signal maintenance crew scheduling problem in the Danish railway system. The problem contains many...... to feed as ‘warm start’ solutions to a Mixed Integer Programming (MIP) solver for further optimisation. We apply the CP/MIP framework to a section of the Danish rail network and benchmark our results against both direct application of a MIP solver and modelling the problem as a Constraint Optimisation...

Predictive Maintenance--An Effective Money Saving Tool Being Applied in Industry Today.

Science.gov (United States)

Smyth, Tom

2000-01-01

Looks at preventive/predictive maintenance as it is used in industry. Discusses core preventive maintenance tools that must be understood to prepare students. Includes a list of websites related to the topic. (JOW)

Improving the TRIGA facility maintenance by predictive maintenance techniques

International Nuclear Information System (INIS)

Preda, M.; Sabau, C.; Barbalata, E.

1997-01-01

This work deals with the specific operation of equipment in radioactive environment or in conditions allowing radioactive contamination. The requirements of remote operation ensuring the operators' protection are presented. Also, the requirements of international standards issued by IAEA-Vienna are reviewed. The organizational withdraws of the maintenance activities, based on the standards and maintenance and repair directives still in force, are shown. It is emphasized the fact that this type of maintenance was adequate to a given level of technical development, characteristic for pre-computerized industry, but, at present, it is obsolete and uneconomic both in utilization and maintenance. Such a system constitutes already a burden hindering the efforts of maximizing the availability, maintenance, prolongation the service life of equipment and utilities, finally, of increasing the efficiency of complex installations. Moreover, the predictive maintenance techniques are strongly requested by the character of radioactive installations precluding the direct access in given zones (a potential risk of irradiation or radioactive contamination) of installations during operation. The results obtained by applying the predictive maintenance techniques in the operation of the double circuit irradiation loop, used in the TRIGA reactors, are presented

Maintenance Decision Making based on different types of data fusion

OpenAIRE

Galar, D.; Gustafson, A.; Tormos Martínez, Bernardo Vicente; Berges, Luis

2012-01-01

[EN] Over the last decade, system integration is applied more as it allows organizations to streamline business processes. A recent development in the asset engineering management is to leverage the investment already made in process control systems. This allows the operations, maintenance, and process control teams to monitor and determine new alarm level based on the physical condition data of the critical machines. Condition-based maintenance (CBM) is a maintenance philosophy base...

Evaluation of the adequacy of maintenance tasks using the failure consequences of railroad vehicles

International Nuclear Information System (INIS)

Kim, Jaehoon; Jeong, Hyun- Yong

2013-01-01

The purpose of this study is to improve the efficiency, reliability and safety related to railroad maintenance tasks through an evaluation of the consequences of failures. The brake system was selected based on the failure data obtained from railroad vehicles in operation as one of the safety systems in railroad vehicles. The failure causes, failure effects, and the criticality of the failure mode were drawn for 62 failure modes of the braking system through the use of an FMECA for the 30 sub-devices having primary functions. The various maintenance tasks for the braking system were categorized into the 62 failure modes and failure consequences using the FMECA and the logic of maintenance decisions. Braking systems manufactured by the same manufacturer and operated by two different operators were studied in an effort to analyze preventive maintenance and to evaluate the adequacy of preventive maintenance tasks for the 62 failure modes. Based on results of the evaluation of these preventive maintenance tasks, new maintenance tasks were proposed, and concrete cost-cutting effects were determined from the calculation of the maintenance time and expected costs, using a preventive maintenance template developed specifically for railroad vehicles

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

Directory of Open Access Journals (Sweden)

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.

Operation and maintenance manual of the accelerator installed in the facility of radiation standards

International Nuclear Information System (INIS)

Fujii, Katsutoshi; Kawasaki, Katsuya; Kowatari, Munehiko; Tanimura, Yoshihiko; Kajimoto, Yoichi; Shimizu, Shigeru

2006-08-01

4MV Van de Graff accelerator was installed in the Facility of Radiation Standards (FRS) in June 2000, and monoenergetic neutron calibration fields and high energy γ-ray calibration fields have been developed. The calibration fields are provided for R and D on dosimetry, and for the calibration and type-test of radiation protection instruments. This article describes the operational procedure, the maintenance work and the operation of the related apparatuses of the accelerator. This article focuses on the sufficient safety and radiation control for the operators, the maintenance performance of the accelerator, and on the prevention of the malfunction due to the mistakes of the operators. This article targets the unexperienced engineers in charge of operation and maintenance of the accelerator. (author)

Long-period maintenance program of JRR-3M

International Nuclear Information System (INIS)

Murayama, Yoji; Onozaki, Michio; Kakefuda, Kazuhiro

1999-01-01

The JRR-3M is a swimming pool type research reactor with maximum thermal output of 20 MW, classed in a large-scale research reactor and composed of numerous facilities. An operation cycle consists of 4 weeks of continuously reactor operation and 1 week of shutdown work such as fuel exchange and irradiation sample handling. The temporary and small-scale maintenance is also carried out during the shutdown period. Systematic maintenance period through a year usually follows 2 stages. The former stage of about 4 weeks is prepared to maintain the general facilities related to the overall reactor system such as computer system. The latter stage of about 9 weeks is prepared to maintain the other individual facilities such as cooling facilities and control facilities that are to be inspected by the regulatory body. Since preventive maintenance is required in order to achieve an improvement of safety, reliability and availability throughout the life cycle of the reactor, a long-period maintenance program should be prepared properly in consideration of an ageing degradation of the facilities. The long-period maintenance program of JRR-3M, which determines not only the replacement frequency but also the maintenance frequency of the facilities, is made on the basis of an ageing degradation of the facilities, irradiation effects of the materials, recommendations from the manufacturer and JRR-3M maintenance records. The replacement frequency recommended by the manufacturer is examined from the viewpoint of the safety significance of the facilities and availability of the components. The program is arranged so that it may not concentrate the replacement of the facilities in the specific fiscal year and smooth the budget and maintenance period throughout the life cycle of the reactor. There have been two unanticipated failures of the facilities, which required rearranging the program. (author)

Application of Bayesian statistical decision theory for a maintenance optimization problem

International Nuclear Information System (INIS)

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

MOV predictive maintenance program at Darlington NGS

International Nuclear Information System (INIS)

Morrison, J.F.

1992-01-01

This paper details the Motor Operated Valve (MOV) Predictive Maintenance program at Darlington Nuclear Generating Station. The program encompasses the use of diagnostics tooling in conjunction with more standard maintenance techniques, with the goal of improving performance of MOV's. Problems encountered and solutions developed during the first two phases of this program are presented, along with proposed actions for the final trending phase of the program. This paper also touches on the preventive and corrective maintenance aspects of an overall MOV maintenance program. 6 refs., 6 tabs., 6 figs

Developing a theoretical maintenance model for disordered eating in Type 1 diabetes.

Science.gov (United States)

Treasure, J; Kan, C; Stephenson, L; Warren, E; Smith, E; Heller, S; Ismail, K

2015-12-01

According to the literature, eating disorders are an increasing problem for more than a quarter of people with Type 1 diabetes and they are associated with accentuated diabetic complications. The clinical outcomes in this group when given standard eating disorder treatments are disappointing. The Medical Research Council guidelines for developing complex interventions suggest that the first step is to develop a theoretical model. To review existing literature to build a theoretical maintenance model for disordered eating in people with Type 1 diabetes. The literature in diabetes relating to models of eating disorder (Fairburn's transdiagnostic model and the dual pathway model) and food addiction was examined and assimilated. The elements common to all eating disorder models include weight/shape concern and problems with mood regulation. The predisposing traits of perfectionism, low self-esteem and low body esteem and the interpersonal difficulties from the transdiagnostic model are also relevant to diabetes. The differences include the use of insulin mismanagement to compensate for breaking eating rules and the consequential wide variations in plasma glucose that may predispose to 'food addiction'. Eating disorder symptoms elicit emotionally driven reactions and behaviours from others close to the individual affected and these are accentuated in the context of diabetes. The next stage is to test the assumptions within the maintenance model with experimental medicine studies to facilitate the development of new technologies aimed at increasing inhibitory processes and moderating environmental triggers. © 2015 The Authors. Diabetic Medicine © 2015 Diabetes UK.

Applicability of Operational Research Techniques in CANDU Nuclear Plant Maintenance

International Nuclear Information System (INIS)

Doyle, E. Kevin

2002-01-01

As previously reported at ICONE 6 in New Orleans, 1996, and ICONE 9 in Niece, 2001, the use of various maintenance optimization techniques at Bruce has lead to cost effective preventive maintenance applications for complex systems. Innovative practices included greatly reducing Reliability Centered Maintenance (RCM) 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 being put in place. Further cost refinement of the station preventive maintenance strategy whereby decisions are based on statistical analysis of historical failure data is being evaluated. A wide range of Operational Research (OR) literature was reviewed for implementation issues and several encouraging areas were found that will assist in the current effort of evaluating maintenance optimization techniques for nuclear power production. The road ahead is expected to consist first of resolving 25 years of data issues and preserving the data via appropriate knowledge system techniques while post war demographics permit experts to input into the system. Subsequent analytical techniques will emphasize total simplicity to obtain the requisite buy in from Corporate Executives who possibly are not trained in Operational Research. Case studies of containment airlock seal failures are used to illustrate the direct applicability of stochastic processes. Airlocks and transfer chambers were chosen as they have long been known as high maintenance items. Also, the very significant financial consequences of this type of failure will help to focus the attention of Senior Management on the effort. Despite substantial investment in research, improvement in the design of the seal material or configuration has not been achieved beyond the designs completed in the 1980's. Overall, the study showed excellent agreement of the relatively quick stochastic methods with the maintenance programs produced at

Development and Field Application Experience of the Reactor Internal Preventive Maintenance Technology

International Nuclear Information System (INIS)

Kanno, A.; Yoshikubo, F.; Morinaka, R.; Tanaka, M.; Hasegawa, K.; Hatou, H.

2012-01-01

A reactor internal preventive maintenance technology, Water Jet Peening (WJP), has been developed as a stress corrosion cracking (SCC) mitigation technology that has been successfully implemented during refuelling outages at 15 Boiling Water Reactors (BWR) and three (3) Advanced BWRs (during the site construction and in the shop fabrication) in Japan. WJP is one of the most successful underwater peening methods, which utilizes the energy generated from the collapsing of bubbles produced by the cavitating water jet nozzle. The energy produced from the cavitations introduces compressive residual stress on the metal surface and subsurface up to a depth of several hundred micrometers. Most recently, we have successfully applied WJP to the bottom head components and to some cracked areas on the shroud support in the Tokai-2 plant. In the case of the bottom head components, we produced inspection and repair tooling as a contingency in the event SCC was identified and would be required to be repaired prior to the implementation of WJP. (author)

Preventive maintenance. 'Problem recognition style' can be used to segment the market and promote healthier lifestyles.

Science.gov (United States)

Jayanti, R K

1997-01-01

Problem recognition styles--desired state types (DSTs) and actual state types (ASTs)--have an effect on preventive health care decision making. Segmenting the market along these lines can help marketers position products and services to educate and attract people who will not see a doctor unless there is something wrong with them. Both groups expect the same benefits from preventive health care actions, but ASTs fail to act on those expectations. Therefore, marketing strategy touting the benefits of preventive health care might be futile. Educational promotional campaigns aimed at both DSTs and ASTs also are wasteful because DSTs already possess much health knowledge, lead wellness-oriented lifestyles, and practice preventive health behaviors.

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

International Nuclear Information System (INIS)

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

Psychological maintenance as an integrated approach to prevention and correction of professional burning out of the medical staff

Directory of Open Access Journals (Sweden)

V. S. Kucher

2014-01-01

Full Text Available The syndrome of professional burning out is a complex of symptoms and signs evidenced in various negative psychic conditions at individual, interpersonal and organizational levels. It is formed owing to a long mismatch between the requirements of the professional environment and the resources of the expert. Analysis of the preventive and correctional programs as a psychological assistance showed insufficiency of such approach. Creation of preventive and correctional programs within psychological maintenance from the position of involution of professional resources, taking into account the theoretical - methodological basis (the concept, the purposes, tasks, system approach, criteria of efficiency and the subjective-personal resources of counteraction directed at activization to burning out at all stages of professional development is progressive.

Improving nuclear power plant reliability through predictive maintenance

International Nuclear Information System (INIS)

Geilhausen, R.; Kunze, U.

1996-01-01

Maintenance strategies can be assigned to one of three categories: failure maintenance, periodic maintenance or condition-oriented maintenance. The optimum maintenance scheme can be selected on the basis of a cost-benefit analysis but the safety of life and limb or the political climate for NPP can hardly expressed in numbers. The implementation of preventive maintenance needs two preconditions: high-performance instrumentation in the form of stationary and mobile monitoring systems for the determination of the condition of the nuclear power plant components and provision of a tool that can handle both the organization of the work and the evaluation of the results obtained. (authors)

Upgrade of maintenance technologies of Nuclear Power Plants

International Nuclear Information System (INIS)

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)

Contract Service for School Maintenance

Science.gov (United States)

Modern Schools, 1976

1976-01-01

Preventive maintenance can extend useful equipment life in a school building and keep systems running more efficiently. Points to consider before selecting a comprehensive energy management package are listed. (Author/MLF)

Waste minimization, recycling and reuse in operations support services fleet maintenance

International Nuclear Information System (INIS)

Trego, A.L.

1994-01-01

Government regulations and smart business practices demand that organizations dramatically reduce both the type and volume of waste generated by their operations. This article describes successful waste minimization and recycling programs created by the Fleet Maintenance, Operations Support Services Division, Westinghouse Hanford Company. These comprehensive programs have greatly reduced waste formerly produced in maintaining 3,528 government-owned vehicles and nearly 200 emergency power generators at the Hanford Site. The actions are integral to preventing future contamination of the Site as well as to cleaning up the complexity of wastes from almost 50 years of defense production. The results of the Fleet Maintenance programs are impressive, recording cost savings of $290,000 in fiscal year 1993 and $965,000 since 1988

An approach to maintenance optimization where safety issues are important

International Nuclear Information System (INIS)

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.

An approach to maintenance optimization where safety issues are important

Energy Technology Data Exchange (ETDEWEB)

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.

Dietary fats and prevention of type 2 diabetes

OpenAIRE

Risérus, Ulf; Willett, Walter C.; Hu, Frank B.

2008-01-01

Although type 2 diabetes is determined primarily by lifestyle and genes, dietary composition may affect both its development and complications. Dietary fat is of particular interest because fatty acids influence glucose metabolism by altering cell membrane function, enzyme activity, insulin signaling, and gene expression. This paper focuses on the prevention of type 2 diabetes and summarizes the epidemiologic literature on associations between types of dietary fat and diabetes risk. It also s...

Environmental favourable foundries through maintenance activities

Directory of Open Access Journals (Sweden)

A. Saniuk

2015-10-01

Full Text Available Maintenance today contributes to the aim of sustainable development in society, including environmental and energy saving, safety and economical aspects. The main purpose of the paper is to present the role of maintenance in the realization of sustainable developing practices in a foundry industry. Maintenance offers numerous opportunities to reduce the influence of foundry processes on the natural environment and utilize resources more efficiently. Maintenance activities can help to reduce losses and thereby improve the efficiency of the processes used in the production of resources (e.g. raw materials, energy, etc., especially in areas such as: the choice of an appropriate strategy for the maintenance of machinery and equipment (e.g. reactive, preventive, proactive; inventory management of spare parts; lubrication management and management of technology media.

Preventing microvascular complications in type 1 diabetes mellitus

OpenAIRE

Viswanathan, Vijay

2015-01-01

Patients with complications of diabetes such as retinopathy, nephropathy, and cardiovascular complications have increased hospital stay with greater economic burden. Prevention of complications should be started before the onset of type 1 diabetes mellitus (T1DM) by working on risk factors and thereafter by intervention upon confirmatory diagnosis which can prevent further damage to β-cells. The actual risk of getting microvascular complications like microalbuminuria and retinopathy progressi...

Modeling the Hybrid Flow Shop Scheduling Problem Followed by an Assembly Stage Considering Aging Effects and Preventive Maintenance Activities

Directory of Open Access Journals (Sweden)

Seyyed Mohammad Hassan Hosseini

2016-05-01

Full Text Available Scheduling problem for the hybrid flow shop scheduling problem (HFSP followed by an assembly stage considering aging effects additional preventive and maintenance activities is studied in this paper. In this production system, a number of products of different kinds are produced. Each product is assembled with a set of several parts. The first stage is a hybrid flow shop to produce parts. All machines can process all kinds of parts in this stage but each machine can process only one part at the same time. The second stage is a single assembly machine or a single assembly team of workers. The aim is to schedule the parts on the machines and assembly sequence and also determine when the preventive maintenance activities get done in order to minimize the completion time of all products (makespan. A mathematical modeling is presented and its validation is shown by solving an example in small scale. Since this problem has been proved strongly NP-hard, in order to solve the problem in medium and large scale, four heuristic algorithms is proposed based on the Johnson’s algorithm. The numerical experiments are used to run the mathematical model and evaluate the performance of the proposed algorithms.

Two-stage maintenance of a production system with exponentially distributed on and off-periods

NARCIS (Netherlands)

van Dijkhuizen, G.C.; van Harten, Aart

1998-01-01

We consider an on–off production system which is subject to failure during on-periods. In case of a failure, the production system is maintained correctively. In addition, preventive maintenance is carried out to prevent failures. The costs of both preventive and corrective maintenance are modelled

Laboratory services series: a master-slave manipulator maintenance program

International Nuclear Information System (INIS)

Jenness, R.G.; Hicks, R.E.; Wicker, C.D.

1976-12-01

The volume of master slave manipulator maintenance at Oak Ridge National Laboratory has necessitated the establishment of a repair facility and organization of a specially trained group of craftsmen. Emphasis on cell containment requires the use of manipulator boots and development of precise procedures for accomplishing the maintenance of 287 installed units. A very satisfactory computer programmed maintenance system has been established at the Laboratory to provide an economical approach to preventive maintenance

A predictive maintenance approach for improved nuclear plant availability

International Nuclear Information System (INIS)

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.)

Diagnostics of heavy mining equipment during the scheduled preventive maintenance

Science.gov (United States)

Drygin, M. Yu; Kuryshkin, N. P.

2018-01-01

Intensification of production, economic globalization and dramatic downgrade of the workers’ professional skills lead to unacceptable technical state of heavy mining equipment. Equipment maintenance outage reaches 84 % of the total downtime, of which emergency maintenance takes up to 36 % of time, that excesses 429 hours per year fr one excavator. It is shown that yearly diagnostics using methods of non-destructive check allows to reduce emergency downtime by 47 %, and 55 % of revealed defects can be eliminated without breaking the technological cycle of the equipment.

MODELS CONCERNING PREVENTIVE VERIFICATION OF TECHNICAL EQUIPMENT

Directory of Open Access Journals (Sweden)

CÂRLAN M.

2016-12-01

Full Text Available The paper presents three operative models whose purpose is to improve the practice of preventive maintenance to a wide range of technical installations. Although the calculation criteria are different, the goal is the same: to determine the optimum time between two consecutive preventive interventions. The optimum criteria of these models are: - the maximum share of technical entity operating probabilities, in the case of the Ackoff - Sasieni [1] method; -the optimum time interval for preventive verification depending on the preventive-corrective maintenance costs imposed by the deciding factor, for the AsturioBaldin [2] model; - the minimum number of renewals – preventive and/or corrective maintenance operations [3

Paranal maintenance and CMMS experience

Science.gov (United States)

Montano, Nelson

2004-10-01

During the last four years of operations, low technical downtime has been one of the relevant records of the Paranal Observatory. From the beginning of the Very Large Telescope (VLT) project, European Southern Observatory (ESO) has considered the implementation of a proper maintenance strategy a fundamental point in order to ensure low technical down time and preserve the Observatory's assets. The implementation of the maintenance strategy was based on the following aspects: - Strong maintenance sense during the design stage. Line Replacement Unit (LRU) concept, standardization and modularity of the Observatory equipment - Creation of a dedicated team for Maintenance - The implementation of a Computerized Maintenance Management System After four operational years, the result of these aspects has exceeded the expectations; the Observatory has been operating with high availability under a sustainable strategy. The strengths of the maintenance strategy have been based on modern maintenance concepts applied by regular production companies, where any minute of down time involves high cost. The operation of the actual Paranal Maintenance System is based mainly on proactive activities, such as regular inspections, preventive maintenance (PM) and predictive maintenance (PdM) plans. Nevertheless, it has been necessary to implement a strong plan for corrective maintenance (CM). The Spare Parts Strategy has also been an important point linked to the Maintenance Strategy and CMMS implementation. At present, almost 4,000 items related to the Observatory spare parts are loaded into the CMMS database. Currently, we are studying the implementation of a Reliability Centered Maintenance (RCM) project in one of our critical systems The following document presents the actual status of the Paranal Maintenance Strategy and which have been the motivations to implement the established strategy.

9 CFR 416.14 - Maintenance of Sanitation SOP's.

Science.gov (United States)

2010-01-01

... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Maintenance of Sanitation SOP's. 416... ACT SANITATION § 416.14 Maintenance of Sanitation SOP's. Each official establishment shall routinely evaluate the effectiveness of the Sanitation SOP's and the procedures therein in preventing direct...

Research on Application of FMECA in Missile Equipment Maintenance Decision

Science.gov (United States)

Kun, Wang

2018-03-01

Fault mode effects and criticality analysis (FMECA) is a method widely used in engineering. Studying the application of FMEA technology in military equipment maintenance decision-making, can help us build a better equipment maintenance support system, and increase the using efficiency of weapons and equipment. Through Failure Modes, Effects and Criticality Analysis (FMECA) of equipment, known and potential failure modes and their causes are found out, and the influence on the equipment performance, operation success, personnel security are determined. Furthermore, according to the synthetical effects of the severity of effects and the failure probability, possible measures for prevention and correction are put forward. Through replacing or adjusting the corresponding parts, corresponding maintenance strategy is decided for preventive maintenance of equipment, which helps improve the equipment reliability.

The Effects of Relationship Type, Partner Intent, and Gender on the Selection of Relationship Maintenance Strategies.

Science.gov (United States)

Shea, B. Christine; Pearson, Judy C.

1986-01-01

Indicates that relationship type did not affect the maintenance strategies that partners chose; however, the partners' relationship intent and the sex-composition of the dyad had a significant impact on the selection of directness strategies. Suggests that individuals are not necessarily more likely to select directness strategies than balance or…

Weight maintenance as a tight rope walk - a Grounded Theory study

Directory of Open Access Journals (Sweden)

Weinehall Lars

2010-02-01

Full Text Available Abstract Background Overweight and obesity are considerable public health problems internationally as well as in Sweden. The long-term results of obesity treatment are modest as reported by other studies. The importance of extending the focus to not only comprise obesity treatment but also prevention of weight gain is therefore being emphasized. However, despite the suggested change in focus there is still no consensus on how to prevent obesity or maintain weight. This study reports findings from a qualitative study focusing on attitudes, behaviors and strategies important for primary weight maintenance in a middle-aged population. Methods In depth interviews were conducted with 23 maintainers and four slight gainers in Sweden. The interviews were transcribed and an analysis of weight maintenance was performed using Grounded Theory. Results Based on the informants' stories, describing attitudes, behaviors and strategies of importance for primary weight maintenance, a model illustrating the main findings, was constructed. Weight maintenance was seen as "a tightrope walk" and four strategies of significance for this "tightrope walk" were described as "to rely on heritage", "to find the joy", "to find the routine" and "to be in control". Eleven "ideal types" were included in the model to illustrate different ways of relating to the main strategies. These "ideal types" described more specific attitudes and behaviors such as; eating food that is both tasteful and nutritious, and choosing exercise that provides joy. However, other somewhat contradictory behaviors were also found such as; only eating nutritious food regardless of taste, and being physically active to control stress and emotions. Conclusion This study show great variety with regards to attitudes, strategies and behaviors important for weight maintenance, and considerations need to be taken before putting the model into practice. However, the results from this study can be used within

A Simulation Model for Machine Efficiency Improvement Using Reliability Centered Maintenance: Case Study of Semiconductor Factory

Directory of Open Access Journals (Sweden)

Srisawat Supsomboon

2014-01-01

Full Text Available The purpose of this study was to increase the quality of product by focusing on the machine efficiency improvement. The principle of the reliability centered maintenance (RCM was applied to increase the machine reliability. The objective was to create preventive maintenance plan under reliability centered maintenance method and to reduce defects. The study target was set to reduce the Lead PPM for a test machine by simulating the proposed preventive maintenance plan. The simulation optimization approach based on evolutionary algorithms was employed for the preventive maintenance technique selection process to select the PM interval that gave the best total cost and Lead PPM values. The research methodology includes procedures such as following the priority of critical components in test machine, analyzing the damage and risk level by using Failure Mode and Effects Analysis (FMEA, calculating the suitable replacement period through reliability estimation, and optimizing the preventive maintenance plan. From the result of the study it is shown that the Lead PPM of test machine can be reduced. The cost of preventive maintenance, cost of good product, and cost of lost product were decreased.

On line performance monitoring for predictive maintenance [Paper No.: VIA - 2

International Nuclear Information System (INIS)

Gupta, R.K.; Chandra, Rajesh

1981-01-01

There will always be progressive deterioration in the performance of dynamic equipment due to normal inevitable wear, malfunctions, failures and other reasons. In most cases it is possible to monitor some parameters of a system which would get progressively affected with the deterioration in the health of the system. By on-line monitoring of such predetermined parameters, compared with preset base data generated for a healthy system earlier, would prove very helpful in avoiding breakdowns and in proper planning of preventive and predictive maintenance. With increasing use of on-line computerised controls the generation of design base data and also the in-built self checking feature of monitoring the equipment health can be achieved by incorporating suitable software. This type of system will be helpful in: (a) predicting the life of component, (b) prewarning the operator about impending malfunctions, (c) establishing a maintenance schedule and spare inventory, and (d) analysing the failures. This type of centralised predictive maintenance is increasingly becoming important where: (a) the number of equipments are large, (b) the operation of equipment is critical from safety criteria, and (c) the minimum safety margin in the performance of the component is to be maintained. Keeping this in mind, the Fuel Handling System of Narora Atomic Power Project and the future power plants having computerised controls will have facility for on-line performance monitoring for predictive maintenance. The paper also describes methodology of the technique in detail, with a few representative cases. (author)

Integrated batch production and maintenance scheduling for multiple items processed on a deteriorating machine to minimize total production and maintenance costs with due date constraint

Directory of Open Access Journals (Sweden)

Zahedi Zahedi

2016-04-01

Full Text Available This paper discusses an integrated model of batch production and maintenance scheduling on a deteriorating machine producing multiple items to be delivered at a common due date. The model describes the trade-off between total inventory cost and maintenance cost as the increase of production run length. The production run length is a time bucket between two consecutive preventive maintenance activities. The objective function of the model is to minimize total cost consisting of in process and completed part inventory costs, setup cost, preventive and corrective maintenance costs and rework cost. The problem is to determine the optimal production run length and to schedule the batches obtained from determining the production run length in order to minimize total cost.

Discounted cost model for condition-based maintenance optimization

International Nuclear Information System (INIS)

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.

The human factor in maintenance work

International Nuclear Information System (INIS)

Hansson, B.

1996-01-01

In most of the maintenance works performed at operating plants, the personnel is the warranty for both efficient performance and good quality. To reach the right quality level in performance, the personnel needs adequate tools and of course a maintenance strategy and an organisation that supports the efficient work. The human factor is mostly referred to when something went wrong and analyses are done. There is a great potential of doing preventive analysis. The presentation will focus on experience in this field and what has been done at Barsebaeck NPP to analyse and improve the maintenance work. As maintenance work can't be seen as an isolated area, the rest of the plant organisation is included in the presentation. (author) figs., tabs

Maintenance for the Millennium: Another Approach

International Nuclear Information System (INIS)

Sculthorpe, Barruy R.

2002-01-01

Nuclear units nationwide are struggling to increase plant reliability and availability while at the same time reduce their operating and maintenance costs. Some very costly investments have been made in programs such as Reliability Centered Maintenance [RCM]. Florida Power and Light's approach at the St. Lucie Nuclear Plant has taken a slightly different approach. Building on our knowledge of the RCM process and an already existing 'World Class' Predictive Maintenance Program, a 'Condition-Based' Maintenance Program that takes advantage of the RCM philosophy and our toolbox full of advanced and highly successful predictive maintenance technologies. These tools currently consist of vibration analysis, lubricant analysis (both physical property and wear metals analysis, thermographic analysis, motor current signature analysis, tribology and process parameter trending. All employed with the intent to evaluate a machines health. This machine health check allows the forecasting of future preventative maintenance [PM's] tasks and the revision of existing PM's to maximize machine performance and eliminate 'no-value-added' maintenance activities/costs. Within the last year, the Condition-Based Maintenance Program has produced a cost saving of approximately $1.5 million dollars. As the program matures, these cost savings will accumulate well into the millennium. (authors)

Suncor maintenance and reliability

Energy Technology Data Exchange (ETDEWEB)

Little, S. [Suncor Energy, Calgary, AB (Canada)

2006-07-01

Fleet maintenance and reliability at Suncor Energy was discussed in this presentation, with reference to Suncor Energy's primary and support equipment fleets. This paper also discussed Suncor Energy's maintenance and reliability standard involving people, processes and technology. An organizational maturity chart that graphed organizational learning against organizational performance was illustrated. The presentation also reviewed the maintenance and reliability framework; maintenance reliability model; the process overview of the maintenance and reliability standard; a process flow chart of maintenance strategies and programs; and an asset reliability improvement process flow chart. An example of an improvement initiative was included, with reference to a shovel reliability review; a dipper trip reliability investigation; bucket related failures by type and frequency; root cause analysis of the reliability process; and additional actions taken. Last, the presentation provided a graph of the results of the improvement initiative and presented the key lessons learned. tabs., figs.

A development of maintenance educational support method by using navigation method. Pt. 3. A detal design of RHR pump maintenance educational support prototype system

International Nuclear Information System (INIS)

Yoshino, Kenji; Hirotsu, Yuko; Fujimoto, Junzo; Tsumura, Joji

2003-01-01

This research establishes the new maintenance educational support prototype system for aiming at organization as Trinity (a supervision person, a construction person in charge, a work person in charge, and group length), and improvement in human reliability for the purpose of aiming at before hand prevention of a systematic error, human error, and the accident and a trouble. Main results: (1) This paper prototype system acquired a participant data by the input of 'position and rank' etc. of a participant, and was taken as the structure which navigates the participant exactly from the start of RHR pump maintenance work to the end on the basis of the data (question etc.) while performing reeducation based on the reply of an organization, organization, and the participant to the structure-ized question in connection with on-site work, judging, and the judgment result etc. by the system. (2) RHR pump maintenance work has the complicated hierarchy. Then, in order to raise the study effect of the participant about maintenance education, it considered as the structure as which that a participant does what study, further to which process a participant next progresses in which protion of the whole maintenance process a participant is and etc. A participant can always keep regarding the whole study in connection with maintenance education (Fig. 2). (3) This paper prototype system was taken as the structure which shows clearly a participant special feature, weak point, etc., by plotting an organization, organization, and the reply result of the subject of the question completion before in connection with on-site work, and after completion on the same screen. (4) This paper prototype system Judge how changed a participant action pattern's completion front, and after completion. For example, from the organization neglect/duty neglect type before completion, after completion specifies having changed to the organization/duty serious-consideration type, further, is adding the

Filling machine preventive maintenance using age replacement method in PT Lucas Djaja

Directory of Open Access Journals (Sweden)

Mustofa Fifi Herni

2018-01-01

Full Text Available PT Lucas Djaja is a company engaged in the pharmaceutical industry which produce sterile drugs and non-sterile. Filling machine has a high failure rate and expensive corrective maintenance cost. PT Lucas Djaja has a policy to perform engine maintenance by way of corrective maintenance. The study focused on the critical components, namely bearing R2, bearing 625 and bearing 626. When the replacement of the failure done by the company is currently using the formula mean time to failure with the result of bearing R2 at point 165 days, bearing 625 at a point 205 days, and bearing 626 at a point 182 days. Solutions generated by using age replacement method with minimization of total maintenance cost given on the bearing R2 at a point 60 days, bearing 625 at the point of 80 days and bearing 626 at a point 40 days.

A VITAL service for predictive MOV maintenance

International Nuclear Information System (INIS)

Anon.

1990-01-01

Motor-operated valve (MOV) maintenance can be a major contributor to unplanned plant downtime, either because valve malfunctions cause unscheduled outages, or because unnecessary valve maintenance lengthens scheduled outages. The cause of both situations is a preventive approach to valve maintenance, where maintenance is scheduled according to a timetable instead of according to a demonstrated need. To move towards a predictive maintenance approach, inexpensive methods of collecting and diagnosing real-time data on the conditions of a valve must be made available. Such a system must be capable of detecting and diagnosing degrading mechanical and electrical behaviour at an early stage, as well as being able to predict the time of failure. Without this data, a predictive approach to maintenance is impossible. Westinghouse is addressing the requirements for a predictive approach to MOV maintenance with the introduction of a third-generation of diagnostic systems for motor-operated valves -the portable Valve Intelligent Test and Analysis System (VITALS) and the on-line Valve Monitoring System (VMS). (author)

"Small Steps, Big Rewards": You Can Prevent Type 2 Diabetes

Science.gov (United States)

... Steps, Big Rewards": You Can Prevent Type 2 Diabetes Past Issues / Winter 2008 Table of Contents For ... million Americans are at risk for type 2 diabetes." "Fifty four million Americans are at risk for ...

Trials in the prevention of type 1 diabetes: current and future.

Science.gov (United States)

Wherrett, Diane K

2014-08-01

A major thrust in type 1 diabetes research is stopping the destruction of beta cells that leads to type 1 diabetes. Research over the past 30 years has defined genetic factors and evidence of autoimmunity that have led to the development of robust prediction models in those at high risk for type 1 diabetes. The ability to identify those at risk and the development of new agents and of collaborative research networks has led to multiple trials aimed at preventing beta cell loss. Trials at all stages of beta cell loss have been conducted: primary prevention (prior to the development of autoimmunity); secondary prevention (after autoantibodies are found) and tertiary prevention (intervening after diagnosis to maintain remaining beta cells). Studies have shown mixed results; evidence of maintained insulin secretion after the time of diagnosis has been described in a number of studies, and primary and secondary prevention is proving to be elusive. Much has been learned from the increasing number of studies in the field in terms of network creation, study design and choice of intervention that will facilitate new avenues of investigation. Copyright © 2014 Canadian Diabetes Association. Published by Elsevier Inc. All rights reserved.

Remote maintenance system for nuclear facilities

International Nuclear Information System (INIS)

Maeda, Masafumi

1993-01-01

In the facilities related to atomic energy, from the viewpoint of the reduction of radiation exposure of workers and the heightening of the rate of operation of the facilities, the development of remote maintenance system is regarded as important. Meidensha Electric Manufacturing Co., Ltd. developed the bilateral control type manipulator, BILARM-83, in 1979, and has developed high performance manipulator systems. As the design of the plant that realizes the remote operation maintenance of process machinery and equipment during plant operation, the remote maintenance system by canyon cell techniques, which was adopted in Savannah River plant, USA, and has been operated for nearly 50 years, has been known. The concept of the full remote maintenance system by large scale cell techniques was shown and has been developed by Power Reactor and Nuclear Fuel Development Corp. In order to realize the remote maintenance of such large scale cells, Meidensha is developing the both arm type bilateral servo manipulator, the single arm type power manipulator, the transport system for moving them, the power and signal system and so on. Those systems were adopted for the glass solidification facilities. (K.I.)

Task types and error types involved in the human-related unplanned reactor trip events

International Nuclear Information System (INIS)

Kim, Jae Whan; Park, Jin Kyun

2008-01-01

In this paper, the contribution of task types and error types involved in the human-related unplanned reactor trip events that have occurred between 1986 and 2006 in Korean nuclear power plants are analysed in order to establish a strategy for reducing the human-related unplanned reactor trips. Classification systems for the task types, error modes, and cognitive functions are developed or adopted from the currently available taxonomies, and the relevant information is extracted from the event reports or judged on the basis of an event description. According to the analyses from this study, the contributions of the task types are as follows: corrective maintenance (25.7%), planned maintenance (22.8%), planned operation (19.8%), periodic preventive maintenance (14.9%), response to a transient (9.9%), and design/manufacturing/installation (6.9%). According to the analysis of the error modes, error modes such as control failure (22.2%), wrong object (18.5%), omission (14.8%), wrong action (11.1%), and inadequate (8.3%) take up about 75% of the total unplanned trip events. The analysis of the cognitive functions involved in the events indicated that the planning function had the highest contribution (46.7%) to the human actions leading to unplanned reactor trips. This analysis concludes that in order to significantly reduce human-induced or human-related unplanned reactor trips, an aide system (in support of maintenance personnel) for evaluating possible (negative) impacts of planned actions or erroneous actions as well as an appropriate human error prediction technique, should be developed

Task types and error types involved in the human-related unplanned reactor trip events

Energy Technology Data Exchange (ETDEWEB)

Kim, Jae Whan; Park, Jin Kyun [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2008-12-15

In this paper, the contribution of task types and error types involved in the human-related unplanned reactor trip events that have occurred between 1986 and 2006 in Korean nuclear power plants are analysed in order to establish a strategy for reducing the human-related unplanned reactor trips. Classification systems for the task types, error modes, and cognitive functions are developed or adopted from the currently available taxonomies, and the relevant information is extracted from the event reports or judged on the basis of an event description. According to the analyses from this study, the contributions of the task types are as follows: corrective maintenance (25.7%), planned maintenance (22.8%), planned operation (19.8%), periodic preventive maintenance (14.9%), response to a transient (9.9%), and design/manufacturing/installation (6.9%). According to the analysis of the error modes, error modes such as control failure (22.2%), wrong object (18.5%), omission (14.8%), wrong action (11.1%), and inadequate (8.3%) take up about 75% of the total unplanned trip events. The analysis of the cognitive functions involved in the events indicated that the planning function had the highest contribution (46.7%) to the human actions leading to unplanned reactor trips. This analysis concludes that in order to significantly reduce human-induced or human-related unplanned reactor trips, an aide system (in support of maintenance personnel) for evaluating possible (negative) impacts of planned actions or erroneous actions as well as an appropriate human error prediction technique, should be developed.

Dietary fats and prevention of type 2 diabetes.

Science.gov (United States)

Risérus, Ulf; Willett, Walter C; Hu, Frank B

2009-01-01

Although type 2 diabetes is determined primarily by lifestyle and genes, dietary composition may affect both its development and complications. Dietary fat is of particular interest because fatty acids influence glucose metabolism by altering cell membrane function, enzyme activity, insulin signaling, and gene expression. This paper focuses on the prevention of type 2 diabetes and summarizes the epidemiologic literature on associations between types of dietary fat and diabetes risk. It also summarizes controlled feeding studies on the effects of dietary fats on metabolic mediators, such as insulin resistance. Taken together, the evidence suggests that replacing saturated fats and trans fatty acids with unsaturated (polyunsaturated and/or monounsaturated) fats has beneficial effects on insulin sensitivity and is likely to reduce risk of type 2 diabetes. Among polyunsaturated fats, linoleic acid from the n-6 series improves insulin sensitivity. On the other hand, long-chain n-3 fatty acids do not appear to improve insulin sensitivity or glucose metabolism. In dietary practice, foods rich in vegetable oils, including non-hydrogenated margarines, nuts, and seeds, should replace foods rich in saturated fats from meats and fat-rich dairy products. Consumption of partially hydrogenated fats should be minimized. Additional controlled, long-term studies are needed to improve our knowledge on the optimal proportion of different types of fats to prevent diabetes.

Maintenance Optimization of High Voltage Substation Model

Directory of Open Access Journals (Sweden)

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.

GRAPHICAL MODELS OF THE AIRCRAFT MAINTENANCE PROCESS

Directory of Open Access Journals (Sweden)

Stanislav Vladimirovich Daletskiy

2017-01-01

Full Text Available The aircraft maintenance is realized by a rapid sequence of maintenance organizational and technical states, its re- search and analysis are carried out by statistical methods. The maintenance process concludes aircraft technical states con- nected with the objective patterns of technical qualities changes of the aircraft as a maintenance object and organizational states which determine the subjective organization and planning process of aircraft using. The objective maintenance pro- cess is realized in Maintenance and Repair System which does not include maintenance organization and planning and is a set of related elements: aircraft, Maintenance and Repair measures, executors and documentation that sets rules of their interaction for maintaining of the aircraft reliability and readiness for flight. The aircraft organizational and technical states are considered, their characteristics and heuristic estimates of connection in knots and arcs of graphs and of aircraft organi- zational states during regular maintenance and at technical state failure are given. It is shown that in real conditions of air- craft maintenance, planned aircraft technical state control and maintenance control through it, is only defined by Mainte- nance and Repair conditions at a given Maintenance and Repair type and form structures, and correspondingly by setting principles of Maintenance and Repair work types to the execution, due to maintenance, by aircraft and all its units mainte- nance and reconstruction strategies. The realization of planned Maintenance and Repair process determines the one of the constant maintenance component. The proposed graphical models allow to reveal quantitative correlations between graph knots to improve maintenance processes by statistical research methods, what reduces manning, timetable and expenses for providing safe civil aviation aircraft maintenance.

Improvement of the preventive maintenance program of an emergency diesel generator set

International Nuclear Information System (INIS)

Jacquot, J.P.; Meuwisse, C.; Cailleaux, J.P.

1995-01-01

An exhaustive Reliability Centered Maintenance (RCM) analysis was performed of the emergency diesel generator sets in Electricite de France 900-MW nuclear power plants. The first part of this paper describes the Reliability Centered Maintenance approach, including the functional breakdown, complete analysis of operation feedback and safety assessment of the risk induced by functional diesel failures. The second part shows how this kind of RCM analysis can be used to improve the efficiency of periodic tests of the machine, and more generally, the efficiency of condition-directed maintenance tasks. The underlying objective is to minimize risk and aging of the machine

Rail for inspection/maintenance device in TOKAMAK type container of a thermonuclear reactor

International Nuclear Information System (INIS)

Takahashi, Kenji.

1996-01-01

A circular rail divided into four arcuate parts for an inspection/maintenance device which runs in a TOKAMAK type container is disposed. Each of the divided rails is supported at the center of the outer surface rotatably by extendable rail supporting shafts. Each of the divided rail is constituted such that it can be contained between limiters disposed at the outer side of the TOKAMAK container when each of the rail support shafts is contracted. With such a constitution, each of the rail support shafts and arcuate rail is contracted and rotated from the outside of the TOKAMAK type container by an actuator. In order to form a circular rail, each of the rail support shafts is extended toward the center of the TOKAMAK type container, and then each of the arcuate rails is rotated into a horizontal state. Then, the joint portions of each of the arcuate rails are connected by using remote controllable locking rods. (I.S.)

Optimal Maintenance of a Production System with Intermediate Buffers

Directory of Open Access Journals (Sweden)

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.

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

International Nuclear Information System (INIS)

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.

Forming a cohesive steam generator maintenance strategy

International Nuclear Information System (INIS)

Poudroux, G.

1991-01-01

In older nuclear plants, steam generator tube bundles are the most fragile part of the reactor coolant system. Steam generator tubes are subject to numerous types of loading, which can lead to severe degradation (corrosion and wear phenomena). Preventive actions, such as reactor coolant temperature reduction or increasing the plugging limit and their associated analyses, can increase steam generator service life. Beyond these preventive actions, the number of affected tubes and the different locations of the degradations that occur often make repair campaigns necessary. Framatome has developed and qualified a wide range of treatment and repair processes. They enable careful management of the repair campaigns, to avoid reaching the maximum steam generator tube plugging limit, while optimizing the costs. Most of the available repair techniques allow a large number of affected tubes to be treated. Here we look only at those techniques that should be taken into account when defining a maintenance strategy. (author)

A bivariate process model for maintenance and inspection planning

NARCIS (Netherlands)

Newby, M.J.; Barker, C.T.

2006-01-01

The paper describes decision making about monitoring and maintenance of systems described by a general stochastic process. The system is monitored and preventive and corrective maintenance actions are carried out in response to the observed system state. The decision process is simplified by using

Stochastic maintenance optimization at Candu power plants

International Nuclear Information System (INIS)

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)

Reliability centered maintenance streamlining through lessons learned

International Nuclear Information System (INIS)

Strong, D.K.

1991-01-01

In late 1986, PSE and G concluded that the Nuclear Department would develop a consistent approach to maintenance at Artificial Island (Salem and Hope Creak nuclear units). Preventive maintenance (PM) would be the heart of this approach. In the last six months of 1987 departments affected by the maintenance program participated on working groups that developed the Artificial Island maintenance philosophy. The central theme of the maintenance philosophy is the RCM (reliability centered maintenance) process. A pilot project tested the process in 1988. In 1989 the Central PM Group formed and in 1990 was given responsibility and authority to analyze, approve, implement, and control PM program changes. RCM is the central theme of the PM improvement effort but not the whole effort. Other important pieces included in this paper are: development of a common PM program, improvement of work instructions, development of predictive maintenance techniques into programs, development of a PM basis database, development of PM feedback from failure trends, root cause analysis, maintenance performance indicators, technicians, and engineers

Planning and control of maintenance systems modelling and analysis

CERN Document Server

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...

Evaluation of implementation an Integrated Safety and Preventive Maintenance System for Improving of Safety Indexes

Directory of Open Access Journals (Sweden)

I mohammadfam

2014-03-01

Full Text Available Accident analysis shows that one of the main reasons for accidents is non-integration of maintenance units with safety. Merging these two processes through an integrated system can reduce and or eliminate accidents, diseases, and environmental pollution. These issues lead to improvement in organizational performance, as well. The aim of this study is to design and establish an integrated system for obtaining the aforementioned goal. Integration was carried out at Nirou Moharreke Machine Tools Company via Structured System Analysis & Design Method (SSADM. In order to measure the effectiveness of the system, selected indexes were compared using statistical methods prior and after system establishment. Results show that the accident severity index reduced from 135.46 in 2010, to 43.85 in 2012. Moreover, system effectiveness improved equipment reliability and availability (e.g. reliability of the Pfeiffer Milling machine (P (t>50 increased from 0.89 in 2010, to 0.9 in 2012. This system by forecasting various failures, and planning and designing the required operations for preventing occurrence of these failures, plays an important role in improving safety conditions of equipment, and increasing organizational performance, and is capable of presenting an excellent accident prevention program.

On Different Maintenance Strategies for Casted Components of Offshore Wind Turbines

DEFF Research Database (Denmark)

Ambühl, Simon; Sørensen, John Dalsgaard

. This maintenance tool uses Crude Monte Carlo Simulations to estimate the expected maintenance costs. Corrective and preventive maintenance strategies with a constant inspection interval or a condition monitoring system are considered. Furthermore, transportation from shore to the wind turbines by boat...... and transportation strategy. The case study shows that the maintenance expenses of casted components correspond to roughly 5% of the overall expected maintenance costs when using a corrective maintenance strategy. This amount can be decreased to roughly 2% when using a condition monitoring system and following...

On maintenance management of wind and nuclear power plants

International Nuclear Information System (INIS)

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

Case Based Asset Maintenance for the Electric Equipment

International Nuclear Information System (INIS)

Kim, Ji-Hyeon; Jung, Jae-Cheon; Chang, Young-Woo; Chang, Hoon-Seon; Kim, Jae-Cheol; Kim, Hang-Bae; Kim, Kyu-Ho; Hur, Yong; Lee, Dong-Chul

2006-01-01

The electric equipment maintenance strategies are changing from PM(Preventive Maintenance) or CM(Corrective Maintenance) to CBM(Condition Based Maintenance). The main benefits of CBM are reduced possibility of service failures of critical equipment and reduced costs or maintenance work. In CBM, the equipment status need to be monitored continuously and a decision should be made whether an equipment need to be repaired or replaced. For the maintenance decision making, the CBR(Case Base Reasoning) system is introduced. The CBR system receives the current equipment status and retrieves the case based historic database to determine any possible equipment failure under current conditions. In retrieving the case based historic data, the suggested DSS(Decision Support System) uses a reasoning engine with an equipment/asset ontology that describes the equipment subsumption relationships

Performance-based maintenance of gas turbines for reliable control of degraded power systems

Science.gov (United States)

Mo, Huadong; Sansavini, Giovanni; Xie, Min

2018-03-01

Maintenance actions are necessary for ensuring proper operations of control systems under component degradation. However, current condition-based maintenance (CBM) models based on component health indices are not suitable for degraded control systems. Indeed, failures of control systems are only determined by the controller outputs, and the feedback mechanism compensates the control performance loss caused by the component deterioration. Thus, control systems may still operate normally even if the component health indices exceed failure thresholds. This work investigates the CBM model of control systems and employs the reduced control performance as a direct degradation measure for deciding maintenance activities. The reduced control performance depends on the underlying component degradation modelled as a Wiener process and the feedback mechanism. To this aim, the controller features are quantified by developing a dynamic and stochastic control block diagram-based simulation model, consisting of the degraded components and the control mechanism. At each inspection, the system receives a maintenance action if the control performance deterioration exceeds its preventive-maintenance or failure thresholds. Inspired by realistic cases, the component degradation model considers random start time and unit-to-unit variability. The cost analysis of maintenance model is conducted via Monte Carlo simulation. Optimal maintenance strategies are investigated to minimize the expected maintenance costs, which is a direct consequence of the control performance. The proposed framework is able to design preventive maintenance actions on a gas power plant, to ensuring required load frequency control performance against a sudden load increase. The optimization results identify the trade-off between system downtime and maintenance costs as a function of preventive maintenance thresholds and inspection frequency. Finally, the control performance-based maintenance model can reduce

Integration of infrared thermography into various maintenance methodologies

Science.gov (United States)

Morgan, William T.

1993-04-01

Maintenance methodologies are in developmental stages throughout the world as global competitiveness drives all industries to improve operational efficiencies. Rapid progress in technical advancements has added an additional strain on maintenance organizations to progressively change. Accompanying needs for advanced training and documentation is the demand for utilization of various analytical instruments and quantitative methods. Infrared thermography is one of the primary elements of engineered approaches to maintenance. Current maintenance methodologies can be divided into six categories; Routine ('Breakdown'), Preventive, Predictive, Proactive, Reliability-Based, and Total Productive (TPM) maintenance. Each of these methodologies have distinctive approaches to achieving improved operational efficiencies. Popular though is that infrared thermography is a Predictive maintenance tool. While this is true, it is also true that it can be effectively integrated into each of the maintenance methodologies for achieving desired results. The six maintenance strategies will be defined. Infrared applications integrated into each will be composed in tabular form.

Identification of Optimal Preventive Maintenance Decisions for Composite Components

NARCIS (Netherlands)

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

THE OFFICIAL AUDIT: THE MAINTENANCE OF THE STRUCTURES AND EQUIPMENTS

Directory of Open Access Journals (Sweden)

Claudio Biglia

2008-12-01

Full Text Available The author distinguishes the ordinary maintenance in corrective, preventive and predictive maintenance and describes the importance of the verifications of the maintenance procedures of the structures and the equipmentes in the food industy. He individualizes criterions to follow for an aware detective check. This approach offers a greater guarantee of food security and a greater responsibility of OSA

Optimal policies for cumulative damage models with maintenance last and first

International Nuclear Information System (INIS)

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.

Interest in use of mHealth technology in HIV prevention and associated factors among high-risk drug users enrolled in methadone maintenance program.

Science.gov (United States)

Shrestha, Roman; Karki, Pramila; Copenhaver, Michael

2017-09-01

The adoption of mobile technologies for health (mHealth) in healthcare has grown considerably in recent years, but systematic assessment of interest in the use of mHealth in HIV prevention efforts among people who use drugs (PWUD) is lacking. We therefore examined interest in use of mHealth technology in HIV prevention and associated individual-level factors among high-risk PWUD enrolled in methadone maintenance program. A total of 400 HIV-negative PWUD, who reported drug- and/or sex-related risk behaviors completed a standardized assessment using audio computer assisted self-interview (ACASI). Results revealed significant interest in using mHealth-based approaches for specific purposes, including: to receive medication reminders (72.3%), to receive information about HIV risk reduction (65.8%), and to assess HIV risk behaviors (76.5%). Multivariate analysis showed that interest in receiving medication reminders was associated with currently taking medication and being neurocognitively impaired, whereas interest in receiving HIV-risk reduction information was associated with being non-white, married, and perceiving the person was at high-risk for contracting HIV. Similarly, participants' interested in using mHealth for HIV risk behavior assessment was associated with having recently visited a healthcare provider and exhibiting depressive symptoms. Overall, this study demonstrated that high-risk PWUD are interested in using mHealth-based tools as a key part of an HIV prevention approach within a common type of drug treatment settings. Thus, formative research on preferences for design and functionality of mHealth-based HIV prevention tools are now needed, followed by practical development, implementation, and evaluation of these new intervention strategies.

The Possibilities of Drug Prevention of Diabetes Mellitus Type 2

Directory of Open Access Journals (Sweden)

V.I. Pankiv

2013-08-01

Full Text Available Over the past few years there have been several randomized controlled trials that examine the effect of lifestyle modification and pharmacological interventions on the likelihood of developing diabetes mellitus (DM type 2 in people at high risk. These studies demonstrated that the number of people newly diagnosed with diabetes within 3–6-year period may be considerably reduced. Therefore focus of discussing the tactics to control DM type 2 is shifted from the relatively narrow topic of treatment of the disease at a wide range of issues of its prophylaxis: prevention of development and early treatment of DM, aimed to stabilization or reverse progression of the disease and prevention of its progression. This review discusses the general concept and the evidence base on preventing DM type 2 in the context of the pathogenesis of the disease. In addition, the attention is paid to the possibilities of the use of the discussed approaches to clinical practice, taking into account pathogenetic features of the disease and and clinical findings.

Improving industrial maintenance contract relationships

NARCIS (Netherlands)

De Jong, A.

2010-01-01

Unavailability of technical systems, such as aircraft, is expensive. Technical systems require maintenance to prevent and to remedy defects that cause unavailability. Users of technical systems usually bear the consequences of the risk of unavailability, in particular the loss of productivity. This

Weight loss maintenance: A review on dietary related strategies

Directory of Open Access Journals (Sweden)

Fatemeh Azizi Soeliman

2014-01-01

Full Text Available Background: Weight regain after weight loss is a common problem for all those obese or overweight who have had a recent weight loss. Different cures such as diet therapy, behavioral therapy, exercise or a mixture of them have been advised as solutions. The purpose of this review is to find the best diet or eating pattern to maintain a recent weight loss. Materials and Methods: We searched in PubMed and SCOPUS by using the following key words: Overweight, obesity, weight maintenance, weight regain, and diet therapy. Finally, we assessed 26 articles in the present article. Results: Meal replacement, low carbohydrate-low glycemic index (GI diet, high protein intake, and moderate fat consumption have shown some positive effects on weight maintenance. However, the results are controversial. A Dietary Approach to Stop Hypertension (DASH-type diet seems helpful for weight maintenance although the need for more study has remained. Some special behaviors were associated with less weight regain, such as, not being awake late at night, drinking lower amount of sugar-sweetened beverages, and following a healthy pattern. Some special foods have been suggested for weight maintenance. However, the roles of specific foods are not confirmed. Conclusion: Healthy diets recommend low carbohydrate, low GI, and moderate fat foods, but it is not clear whether they are useful in preventing weight gain. It seems that consuming fewer calories helps people to keep weight loss. Further research to find strategies in obesity management focusing on successful maintenance of weight loss is needed.

A development of maintenance educational support method by using navigation method. Pt. 1. A conceptual design of RHR pump maintenance educational support prototype system

International Nuclear Information System (INIS)

Yoshino, Kenji; Hirotsu, Yuko; Fujimoto, Junzo; Gouda, Hidenori

2001-01-01

The purpose of this research is before hand prevention of the systematic error produced from the fault of command / command system on the different organization in a nuclear power plant, and the individual error of the demand level of maintenance work, and knowledge and experience level of a maintenance worker produced from it being incongruent (mismatch), and generating of the serious accident and a serious trouble. This research attains optimization with the difficulty of maintenance work, and work execution capability, such as the persons concerned (a supervision person, a construction person, work person), and proposes the new 'maintenance educational support technique' which is useful to the improvement in 'work reliability' and 'before hand prevention of a human error' in the maintenance work spot. The main results concerning this research are shown below. (1) In this research, concept design of RHR pump maintenance work educational support prototype system was performed on the basis of the examination result of a process analysis of RHR pump maintenance work, load mapping, a rule base/knowledge base and a data base/filing system. Consequently, when an educator-ed talked with a data base/filing system along with load mapping of maintenance work (Why, How, What), a possibility that it could reach exactly from work start to the sub goal or the last goal and timely was suggested. (2) As a result of classifying 'the difficulty of maintenance work', and man's work execution capability' and comparing the result using SRK (behavior of human) index which Rasmussen proposed, among both, it turns out that difference (inharmonious) arises. The exact presentation of the educational method or educational material which responded to knowledge and experience level of an educational achievement target or an educator-ed can be referred to as being connected with the improvement in work reliability, and before hand prevention of a human error as a result by then, incorporating

Condition based maintenance pilot projects at Pickering ND

International Nuclear Information System (INIS)

Zemdegs, R.T.

1995-01-01

Ontario Hydro has recognized that the approaches to maintenance have undergone significant changes to the past decades. The traditional break down maintenance approach has been replaced by preventative maintenance and more recently, by condition based maintenance. The nuclear plants of Ontario Hydro have evaluated on a number of alternative programs to improve their maintenance effectiveness and to reduce costs, including Reliability Centred Maintenance (RCM), call-up review, component-based PM programs, analysis of failure history and so on. Pickering ND (nuclear division) and Ontario Hydro's Nuclear Technologies Services Division, have embarked on a Condition Based Maintenance pilot project to address the above issues as a breakthrough solution for smarter maintenance. The Condition Based Maintenance pilot project will demonstrate an end-to-end process utilizing a Reliability Centred Maintenance structured approach to re-engineer and redefine the existing maintenance programs. The project emphasizes on-condition maintenance where justified, and utilizes an information management tool to provide the required records keeping and analysis infrastructure. This paper briefly describes the planned maintenance model at Pickering ND used to guide the CBM pilot, and an overview of the methodology used to develop on-condition equipment indicators as part of a re-engineered maintenance plan

Heuristics for the Economic Production Quantity Problem under Restrictions on Production and Maintenance Time

Directory of Open Access Journals (Sweden)

Qi Xu

2016-01-01

Full Text Available This paper proposes an economic production quantity problem with the maximal production run time and minimal preventive maintenance time over a finite planning horizon. The objective is to find the efficient production and maintenance policy to minimize the total cost composed of production, maintenance, shortages, and holding costs under the restriction on the production run time and the preventive maintenance time. The production and maintenance decisions include the production and maintenance frequencies and the production run and the maintenance time. The variability and the boundedness of the production run and maintenance time make the problem difficult to solve. Two heuristic algorithms are developed using different techniques based on the optimal properties of the relaxed problem. The performance comparison between the two algorithms is illustrated by numerical examples. The numerical results show that, for the most part, there exists a heuristic algorithm which is more effective than the other.

'Omics'-driven discoveries in prevention and treatment of type 2 diabetes

DEFF Research Database (Denmark)

Gjesing, Anette Marianne Prior; Pedersen, Oluf

2012-01-01

as type 2 diabetes risk assessment tools. Recently, however, panels of multiple biomarkers reflecting several pre-diabetic pathologies have been developed. Their specificity and potentials for future risk stratification are discussed. As a multifactorial disorder type 2 diabetes calls for a multifactorial...... treatment approach targeting multiple but modifiable vascular risk factors. The same holds for pre-diabetic states and prevention hereof. In addition, type 2 diabetes and pre-diabetes show major heterogeneity between affected individuals in pathology, risk of organ damages, progression rate...... and responsiveness to treatment or prevention. Despite the heterogeneity and uniqueness of type 2 diabetes and pre-diabetes most affected individuals are currently offered interventions as if they all have the same disease or risk of disease and will respond similarly. The complex origin and course of type 2...

Optimizing the Primary Prevention of Type-2 Diabetes in Primary Health Care

Science.gov (United States)

2017-08-18

Interprofessional Relations; Primary Health Care/Organization & Administration; Diabetes Mellitus, Type 2/Prevention & Control; Primary Prevention/Methods; Risk Reduction Behavior; Randomized Controlled Trial; Life Style

Condition-Based Maintenance Strategy for Production Systems Generating Environmental Damage

Directory of Open Access Journals (Sweden)

L. Tlili

2015-01-01

Full Text Available We consider production systems which generate damage to environment as they get older and degrade. The system is submitted to inspections to assess the generated environmental damage. The inspections can be periodic or nonperiodic. In case an inspection reveals that the environmental degradation level has exceeded the critical level U, the system is considered in an advanced deterioration state and will have generated significant environmental damage. A corrective maintenance action is then performed to renew the system and clean the environment and a penalty has to be paid. In order to prevent such an undesirable situation, a lower threshold level L is considered to trigger a preventive maintenance action to bring back the system to a state as good as new at a lower cost and without paying the penalty. Two inspection policies are considered (periodic and nonperiodic. For each one of them, a mathematical model and a numerical procedure are developed to determine simultaneously the preventive maintenance (PM threshold L∗ and the inspection sequence which minimize the average long-run cost per time unit. Numerical calculations are performed to illustrate the proposed maintenance policies and highlight their main characteristics with respect to relevant input parameters.

ngs (Notochord Granular Surface) Gene Encodes a Novel Type of Intermediate Filament Family Protein Essential for Notochord Maintenance in Zebrafish*

Science.gov (United States)

Tong, Xiangjun; Xia, Zhidan; Zu, Yao; Telfer, Helena; Hu, Jing; Yu, Jingyi; Liu, Huan; Zhang, Quan; Sodmergen; Lin, Shuo; Zhang, Bo

2013-01-01

The notochord is an important organ involved in embryonic patterning and locomotion. In zebrafish, the mature notochord consists of a single stack of fully differentiated, large vacuolated cells called chordocytes, surrounded by a single layer of less differentiated notochordal epithelial cells called chordoblasts. Through genetic analysis of zebrafish lines carrying pseudo-typed retroviral insertions, a mutant exhibiting a defective notochord with a granular appearance was isolated, and the corresponding gene was identified as ngs (notochord granular surface), which was specifically expressed in the notochord. In the mutants, the notochord started to degenerate from 32 hours post-fertilization, and the chordocytes were then gradually replaced by smaller cells derived from chordoblasts. The granular notochord phenotype was alleviated by anesthetizing the mutant embryos with tricaine to prevent muscle contraction and locomotion. Phylogenetic analysis showed that ngs encodes a new type of intermediate filament (IF) family protein, which we named chordostatin based on its function. Under the transmission electron microcopy, bundles of 10-nm-thick IF-like filaments were enriched in the chordocytes of wild-type zebrafish embryos, whereas the chordocytes in ngs mutants lacked IF-like structures. Furthermore, chordostatin-enhanced GFP (EGFP) fusion protein assembled into a filamentous network specifically in chordocytes. Taken together, our work demonstrates that ngs encodes a novel type of IF protein and functions to maintain notochord integrity for larval development and locomotion. Our work sheds light on the mechanisms of notochord structural maintenance, as well as the evolution and biological function of IF family proteins. PMID:23132861

ngs (notochord granular surface) gene encodes a novel type of intermediate filament family protein essential for notochord maintenance in zebrafish.

Science.gov (United States)

Tong, Xiangjun; Xia, Zhidan; Zu, Yao; Telfer, Helena; Hu, Jing; Yu, Jingyi; Liu, Huan; Zhang, Quan; Sodmergen; Lin, Shuo; Zhang, Bo

2013-01-25

The notochord is an important organ involved in embryonic patterning and locomotion. In zebrafish, the mature notochord consists of a single stack of fully differentiated, large vacuolated cells called chordocytes, surrounded by a single layer of less differentiated notochordal epithelial cells called chordoblasts. Through genetic analysis of zebrafish lines carrying pseudo-typed retroviral insertions, a mutant exhibiting a defective notochord with a granular appearance was isolated, and the corresponding gene was identified as ngs (notochord granular surface), which was specifically expressed in the notochord. In the mutants, the notochord started to degenerate from 32 hours post-fertilization, and the chordocytes were then gradually replaced by smaller cells derived from chordoblasts. The granular notochord phenotype was alleviated by anesthetizing the mutant embryos with tricaine to prevent muscle contraction and locomotion. Phylogenetic analysis showed that ngs encodes a new type of intermediate filament (IF) family protein, which we named chordostatin based on its function. Under the transmission electron microcopy, bundles of 10-nm-thick IF-like filaments were enriched in the chordocytes of wild-type zebrafish embryos, whereas the chordocytes in ngs mutants lacked IF-like structures. Furthermore, chordostatin-enhanced GFP (EGFP) fusion protein assembled into a filamentous network specifically in chordocytes. Taken together, our work demonstrates that ngs encodes a novel type of IF protein and functions to maintain notochord integrity for larval development and locomotion. Our work sheds light on the mechanisms of notochord structural maintenance, as well as the evolution and biological function of IF family proteins.

Performance measures for world class maintenance

International Nuclear Information System (INIS)

Labib, A.W.

1998-01-01

A main problem in maintenance in general, and in power plants and related equipment in particular, is the lack of a practical, consistent, and adaptive performance measure that provides a focused feedback and integrates preventive and corrective modes of maintenance. The presentation defines concepts of world class and benchmarking. Desirable features in an appropriate performance measure are identified. It then, demonstrates current practices in maintenance and criticises their shortcomings. An alternative model is presented through a case study. The model monitors performance from a general view, and then offers a focused analysis. The main conclusion is that the proposed model offers an adaptive and a dynamic framework, and hence production and maintenance are integrated in a 'real time' environment. The system is also flexible in working with any other criteria whether they are of a quantitative or a qualitative nature. (orig.) 16 refs

Performance measures for world class maintenance

Energy Technology Data Exchange (ETDEWEB)

Labib, A W [Department of Mechanical Engineering, University of Manchester, Institute of Science and Technology, Manchester (United Kingdom)

1999-12-31

A main problem in maintenance in general, and in power plants and related equipment in particular, is the lack of a practical, consistent, and adaptive performance measure that provides a focused feedback and integrates preventive and corrective modes of maintenance. The presentation defines concepts of world class and benchmarking. Desirable features in an appropriate performance measure are identified. It then, demonstrates current practices in maintenance and criticises their shortcomings. An alternative model is presented through a case study. The model monitors performance from a general view, and then offers a focused analysis. The main conclusion is that the proposed model offers an adaptive and a dynamic framework, and hence production and maintenance are integrated in a `real time` environment. The system is also flexible in working with any other criteria whether they are of a quantitative or a qualitative nature. (orig.) 16 refs.

Performance measures for world class maintenance

Energy Technology Data Exchange (ETDEWEB)

Labib, A.W. [Department of Mechanical Engineering, University of Manchester, Institute of Science and Technology, Manchester (United Kingdom)

1998-12-31

A main problem in maintenance in general, and in power plants and related equipment in particular, is the lack of a practical, consistent, and adaptive performance measure that provides a focused feedback and integrates preventive and corrective modes of maintenance. The presentation defines concepts of world class and benchmarking. Desirable features in an appropriate performance measure are identified. It then, demonstrates current practices in maintenance and criticises their shortcomings. An alternative model is presented through a case study. The model monitors performance from a general view, and then offers a focused analysis. The main conclusion is that the proposed model offers an adaptive and a dynamic framework, and hence production and maintenance are integrated in a `real time` environment. The system is also flexible in working with any other criteria whether they are of a quantitative or a qualitative nature. (orig.) 16 refs.

Maintenance program, organization and procedures

International Nuclear Information System (INIS)

Schegk, J.R.R.

1986-01-01

The Rheinisch-Westfaelisches Elektrizitaetswerk AG (RWE) operates two pressurized water reactors (PWR) with 1.200 MW and 1.300 MW and two boiling water reactors (BWR) with an electrical output of 1.300 MW each. The PWR were commissioned in 1975 and 1977 respectively and have so far achieved a cumulative availability of 72%. The BWR started operating in 1984 and 1985. Since than they have been generating with a cumulative availability of 88%. The reliability of the nuclear power stations resulted in a trouble-free operation. For the last two years, the unscheduled non-availability amounted to 3,7% and 6,5% for the PWR and the BWR respectively. These favourable operating results derive inter alia from systematic preventive maintenance and consistent outage management. Apart from the personnel structure in the power stations the functional sequence of planning, control, performance as well as evaluation of maintenance results constitute a closed cycle. In order to ensure and support an effective cooperation of the above mentioned four functional sequences of a cycle, uniform and computer-assisted information and planning aids have been introduced such as task lists, job ordering, time scheduling and materials management. As a result of this preventive maintenance system the average refueling outage period is 35 to 42 days. (orig.)

Double-Shell Tank (DST) Maintenance and Recovery Subsystem Definition Report

International Nuclear Information System (INIS)

SMITH, E.A.

2000-01-01

The description of the Double-Shell Tank (DST) Maintenance and Recovery Subsystem presented in this document was developed to establish its boundaries. The DST Maintenance and Recovery Subsystem consists of new and existing equipment and facilities used to provide tank farm operators logistic support and problem resolution for the DST System during operations. This support will include evaluating equipment status, performing preventive and corrective maintenance, developing work packages, managing spares and consumables, supplying tooling, and training maintenance and operations personnel

The preventive role of type 2 NKT cells in the development of type 1 diabetes.

Science.gov (United States)

Sørensen, Jakob Ørskov; Buschard, Karsten; Brogren, Carl-Henrik

2014-03-01

In the last two decades, natural killer T (NKT) cells have emerged as an important factor in preventing type 1 diabetes (T1D) when investigated in the experimental non-obese diabetic (NOD) mouse model. So far, investigations have largely focused on type 1 NKT cells with invariant T-cell receptors, whereas the role of type 2 NKT cells with diverse T-cell receptors is less well understood. However, there have been several findings which indicate that in fact type 2 NKT cells may regulate the progression of type 1 diabetes in NOD mice, including a fraction of these cells which recognize β-cell-enriched sulfatide. Therefore, the focus for this review is to present the current evidence of the effect of type 2 NKT cells on the development of T1D. In general, there is still uncertainty surrounding the mechanism of activation and function of NKT cells. Here, we present two models of the effector mechanisms, respectively, Th1/Th2 polarization and the induction of tolerogenic dendritic cells (DC). In conclusion, this review points to the importance of immunoregulation by type 2 NKT cells in preventing the development of T1D and highlights the induction of tolerogenic DC as a likely mechanism. The possible therapeutic role of type 1 and type 2 NKT cells are evaluated and future experiments concerning type 2 NKT cells and T1D are proposed. © 2013 APMIS. Published by John Wiley & Sons Ltd.

Scheduling and recording of reactor maintenance and testing by computer

International Nuclear Information System (INIS)

Gray, P.L.

1975-01-01

The use of a computer program, Maintenance Information and Control (MIAC), at the Savannah River Laboratory (SRL) assists a small operating staff in maintaining three research reactors and a subcritical facility. The program schedules and defines preventive maintenance, schedules required periodic tests, logs repair and cost information, specifies custodial and service responsibilities, and provides equipment maintenance history, all with a minimum of record-keeping

An effective manpower planning approach for maintenance ...

African Journals Online (AJOL)

The level of maintenance activities of a cocoa processing factory in Nigeria was studied. Data on critical machine parts involved in the maintenance work were collected and the different jobs carried out according to sections and nature of the activities were classified. The workloads for each type of maintenance activities ...

Remote maintenance in nuclear fuel reprocessing

International Nuclear Information System (INIS)

Herndon, J.N.

1985-01-01

Remote maintenance techniques applied in large-scale nuclear fuel reprocessing plants are reviewed with particular attention to the three major maintenance philosophy groupings: contact, remote crane canyon, and remote/contact. Examples are given, and the relative success of each type is discussed. Probable future directions for large-scale reprocessing plant maintenance are described along with advanced manipulation systems for application in the plants. The remote maintenance development program within the Consolidated Fuel Reprocessing Program at the Oak Ridge National Laboratory is also described. 19 refs., 19 figs

Mobile Health Technology (mDiab) for the Prevention of Type 2 Diabetes: Protocol for a Randomized Controlled Trial.

Science.gov (United States)

Muralidharan, Shruti; Mohan, Viswanathan; Anjana, Ranjit Mohan; Jena, Sidhant; Tandon, Nikhil; Allender, Steven; Ranjani, Harish

2017-12-12

The prevalence of type 2 diabetes is increasing in epidemic proportions in low- and middle-income countries. There is an urgent need for novel methods to tackle the increasing incidence of diabetes. The ubiquity of mobile phone use and access to Internet makes mobile health (mHealth) technology a viable tool to prevent and manage diabetes. The objective of this randomized controlled trial is to implement and evaluate the feasibility, cost-effectiveness, and sustainability of a reality television-based lifestyle intervention program. This intervention program is delivered via a mobile phone app (mDiab) to approximately 1500 Android smartphone users who are adults at a high risk for type 2 diabetes from three cities in India, namely, Chennai, Bengaluru, and New Delhi. The mDiab intervention would be delivered via a mobile phone app along with weekly coach calls for 12 weeks. Each participant will go through a maintenance phase of 6 to 8 months post intervention. Overall, there would be 3 testing time points in the study: baseline, post intervention, and the end of follow-up. The app will enable individuals to track their weight, physical activity, and diet alongside weekly video lessons on type 2 diabetes prevention. The study outcomes are weight loss (primary measure of effectiveness); improvement in cardiometabolic risk factors (ie, waist circumference, blood pressure, glucose, insulin, and lipids); and improvement in physical activity, quality of life, and dietary habits. Sustainability will be assessed through focus group discussions. If successful, mDiab can be used as a model for translational and implementation research in the use of mHealth technology for diabetes prevention and may be further expanded for the prevention of other noncommunicable diseases such as hypertension and cardiovascular diseases. Clinical Trials Registry of India CTRI/2015/07/006011 http://ctri.nic.in/Clinicaltrials/pdf_generate.php? trialid=11841 (Archived by WebCite at http

A mixed methods protocol for developing and testing implementation strategies for evidence-based obesity prevention in childcare: a cluster randomized hybrid type III trial.

Science.gov (United States)

Swindle, Taren; Johnson, Susan L; Whiteside-Mansell, Leanne; Curran, Geoffrey M

2017-07-18

Despite the potential to reach at-risk children in childcare, there is a significant gap between current practices and evidence-based obesity prevention in this setting. There are few investigations of the impact of implementation strategies on the uptake of evidence-based practices (EBPs) for obesity prevention and nutrition promotion. This study protocol describes a three-phase approach to developing and testing implementation strategies to support uptake of EBPs for obesity prevention practices in childcare (i.e., key components of the WISE intervention). Informed by the i-PARIHS framework, we will use a stakeholder-driven evidence-based quality improvement (EBQI) process to apply information gathered in qualitative interviews on barriers and facilitators to practice to inform the design of implementation strategies. Then, a Hybrid Type III cluster randomized trial will compare a basic implementation strategy (i.e., intervention as usual) with an enhanced implementation strategy informed by stakeholders. All Head Start centers (N = 12) within one agency in an urban area in a southern state in the USA will be randomized to receive the basic or enhanced implementation with approximately 20 classrooms per group (40 educators, 400 children per group). The educators involved in the study, the data collectors, and the biostastician will be blinded to the study condition. The basic and enhanced implementation strategies will be compared on outcomes specified by the RE-AIM model (e.g., Reach to families, Effectiveness of impact on child diet and health indicators, Adoption commitment of agency, Implementation fidelity and acceptability, and Maintenance after 6 months). Principles of formative evaluation will be used throughout the hybrid trial. This study will test a stakeholder-driven approach to improve implementation, fidelity, and maintenance of EBPs for obesity prevention in childcare. Further, this study provides an example of a systematic process to develop

Different Transportation and Maintenance Strategies for Offshore Wind Farms

DEFF Research Database (Denmark)

Ambühl, Simon; Sørensen, John Dalsgaard

as different maintenance strategies are considered. The report contains a case study where the presented approach is applied to a wind turbine farm and a sensitivity study of the different parameters like the operational range of the boat/helicopter, the electricity price, real rate of interest, inspection......Inspections as well as transportation of personnel and repair parts are a significant contributor to the levelized cost of energy for offshore wind turbines. There are different operation and maintenance (O&M) strategies for offshore wind turbines. Maintenance can be performed preventively...... of energy using different maintenance and transportation strategies....

Job analysis of maintenance-mechanic position for the nuclear power plant maintenance personnel reliability model

International Nuclear Information System (INIS)

Siegel, A.I.; Bartter, W.D.; Kopstein, F.F.

1982-06-01

The task list method of job survey was used. In collaboration with BWR and PWR personnel, a list of 107 tasks performed by maintenance mechanics was developed, grouped into: remove and install, test and repair, inspect and perform preventive maintenance, miscellaneous, communication, and report preparation. For each listed task, the questionnaire form inquired into: frequency of performance, task completion time, safety consequences of improper performance, and the amount of training required to perform the task proficiently. Scaled information was requested about seven abilities: (1) visual speed, accuracy, and recognition; (2) gross motor coordination; (3) fine manual dexterity; (4) strength and stamina; (5) cognition; (6) memory; and (7) problem solving required for function completion. Survey forms were distributed to 27 nuclear power plants. Thirty-one maintenance mechanics representing 17 plants returned the completed forms. Frequency of performing tasks was bimodally distributed: (1) between once a year and once every six months, and (2) about once a week. More than half of the tasks have potential risk consequences if improperly performed. The five tasks with the greatest risk implications in the case of inadequate performance were: (1) remove and install reactor and dry-well heads, (2) test and repair reactor system components, (3) remove and install pressurizer mechanical relief valves, (4) test and repair pressurizer relief valves, (5) remove and install core spray pumps, seals, and valves. Hierarchically, the public risk associated with the various functions was: (1) remove and install, (2) test and repair, (3) preventive maintenance, (4) miscellaneous tasks, (5) communication, and (6) report preparation

The missing link between maintenance contracts and flexible asset management

OpenAIRE

Marttonen-Arola, Salla; Viskari, Sari; Kärri, Timo

2013-01-01

The paper shows how additional value can be created in maintenance collaboration through integrating the features of flexible asset management into maintenance contracts. We expand the traditional typology of maintenance contracts and introduce a new contract type, flexible asset management contracts. Also value sharing in the new contract type is discussed. Our logic for sharing the value is based on reaching for win-win situations in industrial maintenance collaboration. Finally, we present...

Rotating Machinery Predictive Maintenance Through Expert System

Directory of Open Access Journals (Sweden)

M. Sarath Kumar

2000-01-01

Full Text Available Modern rotating machines such as turbomachines, either produce or absorb huge amount of power. Some of the common applications are: steam turbine-generator and gas turbine-compressor-generator trains produce power and machines, such as pumps, centrifugal compressors, motors, generators, machine tool spindles, etc., are being used in industrial applications. Condition-based maintenance of rotating machinery is a common practice where the machine's condition is monitored constantly, so that timely maintenance can be done. Since modern machines are complex and the amount of data to be interpreted is huge, we need precise and fast methods in order to arrive at the best recommendations to prevent catastrophic failure and to prolong the life of the equipment. In the present work using vibration characteristics of a rotor-bearing system, the condition of a rotating machinery (electrical rotor is predicted using an off-line expert system. The analysis of the problem is carried out in an Object Oriented Programming (OOP framework using the finite element method. The expert system which is also developed in an OOP paradigm gives the type of the malfunctions, suggestions and recommendations. The system is implemented in C++.

Initiating stochastic maintenance optimization at Candu Power Plants

International Nuclear Information System (INIS)

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)

Guide for generic application of Reliability Centered Maintenance (RCM) recommendations

International Nuclear Information System (INIS)

Schwan, C.A.; Toomey, G.E.; Morgan, T.A.; Darling, S.S.

1991-02-01

Previously completed reliability centered maintenance (RCM) studies form the basis for developing or refining a preventive maintenance program. This report describes a generic methodology that will help utilities optimize nuclear plant maintenance programs using RCM techniques. This guide addresses the following areas: history of the generic methodology development process, and use of the generic methodology for conducting system-to-system and component-to-component evaluations. 2 refs., 2 figs., 5 tabs

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

International Nuclear Information System (INIS)

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

Program strategies for maintenance management, organization and planning

International Nuclear Information System (INIS)

Czegeny, J.I.

2003-01-01

In this paper we look respectively at three specific examples showing program strategies for maintenance management, organization and planning. Starting with preventive maintenance optimization, we will look at one Bruce B Predefined task on the Reactor Regulating System to illustrate reduced maintenance requirement, a maintenance management strategy. Next discussed is the organizational strategy at Darlington to have an engineering program meet the jurisdictional requirements for maintaining certification for TSSA registered pressure vessels. The last look-see will show the earned value of the planning for the first Pickering A unit to be returned to service. Finally all the above is tied together in a compare and contrast of what works and what could be improved upon. (author)

Preventative maintenance plan for emergency pumping trailers

International Nuclear Information System (INIS)

Wiggins, D.D.

1994-09-01

The purpose/goal of this document is to identify the maintenance requirements and resources available to properly maintain the readiness and condition of the Emergency Pumping Equipment controlled by the Tank Waste Remediation System Tank Farms Plant Engineering and Tank Stabilization Operations. This equipment is intended to pump a single-shell tank (SST) that has been identified as an assumed leaking tank. The goal is to commence pumping (submersible or jet) as soon as safely possible after identifying a SST as an assumed leaking tank. Important information pertaining to the Emergency Pumping Equipment, Over-Ground Piping installation, and procedures is found in WHC-SD-WM-AP-005, ''Single Shell Tank Leak Emergency Pumping Guide.''

Probabilistic methods for maintenance program optimization

International Nuclear Information System (INIS)

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)

Elements of a total MOV maintenance program

International Nuclear Information System (INIS)

Lavallee, W.L.

1989-01-01

Establishing a good preventive and predictive maintenance program for motor-operated valves (MOVs) is an especially challenging task for nuclear power plants. Because of the sheer number of MOVs involved, all with somewhat different characteristics and requirements, and the extremely critical functions that some of the MOVs perform, the maintenance program quickly becomes a major exercise in coordination. This paper outlines a three-phase approach to achieving a comprehensive MOV maintenance program. It is based on experience in assisting nuclear plants with their MOV programs and encountering many of the pitfalls that can hamper these programs. The three phases include up-front engineering preparation, field diagnostic testing, and maintenance follow-up and trending. Each of these phases is discussed, and a flowchart describing the individual elements of each phase is provided

Ecological Interface Design of Augmented Reality Display for Nuclear Power Plant Maintenance

International Nuclear Information System (INIS)

Kim, In; Seong, Poong Hyun

2008-01-01

The importance of maintenance in nuclear power plants (NPPs) has been emphasized through many researches. The goals of maintenance in nuclear power plants are not only to reduce the number of shutdowns which directly affects to the profit, but also to prevent accidents or incidents hence improves nuclear safety. It is known that reduction of the rate of human error in maintenance tasks can be achieved if maintenance personnel are properly supported by maintenance support systems. Among many proposed maintenance support system, the use of augmented reality (AR) has been proposed

PENERAPAN MODEL PREVENTIVE MAINTENANCE SMITH DAN DEKKER DI PD. INDUSTRI UNIT INKABA

Directory of Open Access Journals (Sweden)

Hari Adianto

2005-01-01

Full Text Available The globalization era along with fast development of technology%2C industries must try to increase the quantity and quality of products that they have produced. The development of industrial products which have been increase continually need support from fluency of production process. In this case the industrial companies want a high availability system. PD Industri Unit Inkaba is one of the companies that moves in sector rubber technique industry. The company wants the production process go smoothly so that the company can keeps the existence and increases the product’s quality with cost efficiency and can competes with foreign markets. The smoothness of production process needs support from machines or production’s tools that have good condition. To keep the machines in good condition so that they will in the optimal condition when used%2C then the machines need to be maintained. M.A.J. Smith dan R. Dekker develop a model that combine availability model and preventive maintenance and consider the expected uptime and downtime of the system. This model is a 1 out of n system model%2C which has one operating machine and support by (n – 1 unit machine reserves. A 1 out of n system is also applicable to replaceable components. Smith and Dekker’s model gives the expected uptime and downtime of the system approximation that can gives good approximation of long term average operating cost. The results from decision of component preventive replacement age and optimal number of component reserve are expected to be able to keep the reliability system and be able to avoid the decease of availability system because of maintenance activity. Abstract in Bahasa Indonesia : Dalam era persaingan industri yang semakin global disertai perkembangan teknologi yang pesat%2C industri-industri terus berusaha meningkatkan kuantitas dan kualitas produk yang dihasilkannya. Perkembangan hasil industri yang semakin meningkat secara terus-menerus memerlukan dukungan

Non-periodic preventive maintenance with reliability thresholds for complex repairable systems

International Nuclear Information System (INIS)

Lin, Zu-Liang; Huang, Yeu-Shiang; Fang, Chih-Chiang

2015-01-01

In general, a non-periodic condition-based PM policy with different condition variables is often more effective than a periodic age-based policy for deteriorating complex repairable systems. In this study, system reliability is estimated and used as the condition variable, and three reliability-based PM models are then developed with consideration of different scenarios which can assist in evaluating the maintenance cost for each scenario. The proposed approach provides the optimal reliability thresholds and PM schedules in advance by which the system availability and quality can be ensured and the organizational resources can be well prepared and managed. The results of the sensitivity anlysis indicate that PM activities performed at a high reliability threshold can not only significantly improve the system availability but also efficiently extend the system lifetime, although such a PM strategy is more costly than that for a low reliabiltiy threshold. The optimal reliability threshold increases along with the number of PM activities to prevent future breakdowns caused by severe deterioration, and thus substantially reduces repair costs. - Highlights: • The PM problems for repairable deteriorating systems are formulated. • The structural properties of the proposed PM models are investigated. • The corresponding algorithms to find the optimal PM strategies are provided. • Imperfect PM activities are allowed to reduce the occurences of breakdowns. • Provide managers with insights about the critical factors in the planning stage

Operation and maintenance cost data for residential photovoltaic modules/panels

Science.gov (United States)

Oster, J. R., Jr.; Zaremski, D. R., Jr.; Albert, E. M.; Hawkins, S. L.

1980-01-01

Costs associated with the operation and maintenance of residential photovoltaic modules and arrays are studied. Six basic topics related to operation and maintenance to photovoltaic arrays are investigated: maintenance; cleaning; panel replacement; gasket repair/replacement; wiring repair/replacement; and termination repair/replacement. The effects of the mounting types (rack mount, stand off mount, direct mount and integral mount) and the installation/replacement type (sequential, partial interruption and independent) are identified and described. Methods of reducing maintenance costs are suggested.

Development of maintenance engineering system

International Nuclear Information System (INIS)

1995-03-01

Department of JMTR project has developed the Maintenance Engineering System which evaluates the aging tendency of the facilities. The system is used for the repair plan and the replace period of parts, components, equipments or facilities. The system has the data-base which consists of the check data, the inspection data, the trouble data and the repair data at the JMTR since the virgin criticality. The system is utilized maintenance works and concludes the maintenance procedures for the failure components, equipments and facilities. This system has the following characteristics. (1) Anybody can operate the system as easily as word processor. (2) Data are put into by man-machine-interface. (3) The data sheets are with light color and the recognizable arrangements. (4) The system is cost-efficient using commercial personal computers and applications. The research card and the layouts of the input data sheet had been formatted. Data has been begun to be put into the system and to check its functions. The result demonstrates that the system is available for preventive maintenance at the JMTR. (author)

Money-back guarantee warranty policy with preventive maintenance strategy for sensor-embedded remanufactured products

Science.gov (United States)

Alqahtani, Ammar Y.; Gupta, Surendra M.

2018-01-01

In today's global environment, technology is constantly evolving. Being able to stay up-to-date with the very latest technological advances can be extremely hard to accomplish. As a result of these changes and developments in technology, which often come unexpectedly, consumers are frequently tempted to update their devices to the very latest model. The result is that the life cycle of a product is becoming shorter and shorter than before. Manufacturers attempt to respond to consumers' concerns involving environmental issues as well as the more governmentally stringent environmental legislations by establishing facilities which include the minimization of the totality of waste relocated to landfills by recovering materials and components from returned, or End-Of-Life products and reuse them to build a remanufactured product, and/or novel components. With the rapid growth of interest in remanufactured products' market, offering warranty for remanufactured products and components is becoming a necessity for remanufacturer in order to meet customers' requirement and as a marketing mechanism. During that process, maintenance policies are of great importance in order to reduce the warranty cost on the remanufacturer. In this paper, an optimization simulation model for remanufactured items sold with one-dimensional non-renewing money-back guarantee (MBG) warranty policy is proposed from the view of remanufacturer, in which, an End-Of-Life product is subjected to upgrade action at the end of its past life and during the warranty period, preventive maintenance actions are carried out when the remaining life of the product reaches a pre-specified value so that the remanufacturer's expected profit can be maximized. Finally, a numerical example and design of experiment analysis are provided to demonstrate the proposed approach.

Demonstration of reliability centered maintenance

International Nuclear Information System (INIS)

Schwan, C.A.; Morgan, T.A.

1991-04-01

Reliability centered maintenance (RCM) is an approach to preventive maintenance planning and evaluation that has been used successfully by other industries, most notably the airlines and military. Now EPRI is demonstrating RCM in the commercial nuclear power industry. Just completed are large-scale, two-year demonstrations at Rochester Gas ampersand Electric (Ginna Nuclear Power Station) and Southern California Edison (San Onofre Nuclear Generating Station). Both demonstrations were begun in the spring of 1988. At each plant, RCM was performed on 12 to 21 major systems. Both demonstrations determined that RCM is an appropriate means to optimize a PM program and improve nuclear plant preventive maintenance on a large scale. Such favorable results had been suggested by three earlier EPRI pilot studies at Florida Power ampersand Light, Duke Power, and Southern California Edison. EPRI selected the Ginna and San Onofre sites because, together, they represent a broad range of utility and plant size, plant organization, plant age, and histories of availability and reliability. Significant steps in each demonstration included: selecting and prioritizing plant systems for RCM evaluation; performing the RCM evaluation steps on selected systems; evaluating the RCM recommendations by a multi-disciplinary task force; implementing the RCM recommendations; establishing a system to track and verify the RCM benefits; and establishing procedures to update the RCM bases and recommendations with time (a living program). 7 refs., 1 tab

Floors: Care and Maintenance.

Science.gov (United States)

Post Office Dept., Washington, DC.

Guidelines, methods and policies regarding the care and maintenance of post office building floors are overviewed in this handbook. Procedures outlined are concerned with maintaining a required level of appearance without wasting manpower. Flooring types and characteristics and the particular cleaning requirements of each type are given along with…

Spare parts sharing with joint optimization of maintenance and inventory policies

DEFF Research Database (Denmark)

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...

Operation and maintenance strategies for wave energy converters

DEFF Research Database (Denmark)

Ambühl, Simon; Marquis, Laurent; Kofoed, Jens Peter

2015-01-01

costs including costs due to lost electricity production are minimized. The risk-based approach is compared with an approach where only boats are used and another approach where the target is to minimize the downtime of the device. This article presents a dynamic approach for total operation......Inspection and maintenance costs are a significant contributor to the cost of energy for wave energy converters. There are different operation and maintenance strategies for wave energy converters. Maintenance can be performed after failure (corrective) or before a breakdown (preventive) occurs....... Furthermore, a helicopter and boats can be used to transport equipment and personnel to the device, or the whole device can be towed to a harbour for operation and maintenance actions. This article describes, among others, a risk-based inspection and maintenance planning approach where the overall repair...

Operation and maintenance of 1MW PUSPATI TRIGA reactor

International Nuclear Information System (INIS)

Adnan Bokhari; Mohammad Suhaimi Kassim

2006-01-01

The Malaysian Research Reactor, Reactor TRIGA PUSPATI (RTP) has been successfully operated for 22 years for various experiments. Since its commissioning in June 1982 until December 2004, the 1MW pool-type reactor has accumulated more than 21143 hours of operation, corresponding to cumulative thermal energy release of about 14083 MW-hours. The reactor is currently in operation and normally operates on demand, which is normally up to 6 hours a day. Presently the reactor core is made up of standard TRIAGA fuel element consists of 8.5 wt%, 12 wt% and 20 wt% types; 20%-enriched and stainless steel clad. Several measures such as routine preventive maintenance and improving the reactor support systems have been taken toward achieving this long successful operation. Besides normal routine utilization like other TRIGA reactors, new strategies are implemented for effective increase in utilization. (author)

Effectiveness of Relapse Prevention Cognitive-Behavioral Model in Opioid-Dependent Patients Participating in the Methadone Maintenance Treatment in Iran.

Science.gov (United States)

Pashaei, Tahereh; Shojaeizadeh, Davoud; Rahimi Foroushani, Abbas; Ghazitabatabae, Mahmoud; Moeeni, Maryam; Rajati, Fatemeh; M Razzaghi, Emran

2013-08-01

To evaluate the effectiveness of a relapse prevention cognitive-behavioral model, based on Marlatt treatment approach, in Opioid-dependent patients participating in the Methadone Maintenance Treatment (MMT) in Iran. The study consisted of 92 individuals treated with methadone in Iranian National Center of Addiction Studies (INCAS). Participants were randomized into two groups: educational intervention group (N=46) and control group (N=46). The intervention was comprised of 10 weekly 90 minute sessions, done during a period of 2.5 months based on the most high risk situations determined using Inventory Drug Taking Situation instrument. Relapse was defined as not showing up for MMT, drug use for at least 5 continuous days, and a positive urinary morphine test. While, only 36.4% of the intervention group relapsed into drug use, 63.6% of the control group relapsed. The result of the logistic regressions showed that the odd ratio of the variable of intervention program for the entire follow up period was 0.43 (P<0.01). Further, the odd ratio of this variable in one month, three months, and 195 days after the therapy were 0.48 (P<.03), 0.31 (P<.02), and 0.13 (P<.02) respectively that revealed that on average, the probability of relapse among individuals in the intervention group was lower than patients in control group. Relapse prevention model based on Marlatt treatment approach has an effective role in decreasing relapse rate. This model can be introduced as a complementary therapy in patients treated with methadone maintenance.

Graded Approach to the Development of a Contingency Plan for On-Line Maintenance

International Nuclear Information System (INIS)

Chang, Hee Seung; Kim, Jung Wun; Song, Tae Young

2012-01-01

Many utilities perform preventive maintenance for safety systems during power operation to improve equipment reliability so as to focus on the work activities more easily and improve the quality of maintenance. Such a strategy can also reduce outage work activities, thus allowing resources to be utilized effectively. Preventive maintenance during power operation, known as on-line maintenance (OLM), requires an assessment and mitigation of risk, which can increase owing to out-of-service safety systems. One of the mitigation action plans is a contingency plan. EPRI recommends the development of a contingency plan for all planned system outages which include factors that strongly affect safety. The Korea Hydro and Nuclear Power Company (KHNP) undertook the preventive maintenance of the Essential Chilled Water System (ECWS) of a Westinghouse plant as a pilot OLM implementation. During the preparation of the work activities, a contingency plan was a pertinent issue during the discussions with regulators, especially regarding the scope and depth of the plan. This paper discusses the purpose of a contingency plan, including as examples some cases of US utilities, and proposes a graded approach to develop a contingency plan for OLM in consideration of the risks

The meteorological monitoring audit, preventative maintenance and quality assurance programs at a former nuclear weapons facility

International Nuclear Information System (INIS)

Maxwell, D.R.

1995-01-01

The purposes of the meteorological monitoring audit, preventative maintenance, and quality assurance programs at the Rocky Flats Environmental Technology Site (Site), are to (1) support Emergency Preparedness (EP) programs at the Site in assessing the transport, dispersion, and deposition of effluents actually or potentially released into the atmosphere by Site operations; and (2) provide information for onsite and offsite projects concerned with the design of environmental monitoring networks for impact assessments, environmental surveillance activities, and remediation activities. The risk from the Site includes chemical and radioactive emissions historically related to nuclear weapons component production activities that are currently associated with storage of large quantities of radionuclides (plutonium) and radioactive waste forms. The meteorological monitoring program provides information for site-specific weather forecasting, which supports Site operations, employee safety, and Emergency Preparedness operations

Costs of performance based maintenance for local roads: Case study Albania

Science.gov (United States)

Jokanović, Igor; Grujić, Bojana; Zeljić, Dragana; Grujić, Žarko; Svilar, Mila

2017-12-01

The provision and maintenance of road infrastructure is a major global business, consequently it is essential that road maintenance services are provided in the most cost effective manner. Without regular maintenance, roads can rapidly fall into disrepair, preventing realization of the longer term impacts of road improvements on development, such as increased agricultural production and growth in school enrollment, which is of particular importance for a network of local (access) roads. Inadequate local roads maintenance in Albania is proposed to be solved by implementing performance based maintenance approach for which the costing exercise is presented within the paper.

Pavement condition assessment to forecast maintenance program on JKR state roads in Petaling district

Science.gov (United States)

Hamsan, R.; Hafiz, H.; Azlan, A.; Keprawi, M. F.; Malik, A. K. A.; Adamuddin, A.; Abdullah, A. H.; Shafie, A. M.

2018-02-01

This research allows local authorities to project road maintenance in term of activities and financial expenditure through pavement condition assessment and then Highway Development and Management (HDM-4) analysis. Current form of road maintenance carried out by local authority is on reactive manner where corrective actions were taken based on reports recorded. Some went unrecorded hence causing prolonged damages. This causes the local authority unable to project the required cost to maintain the roads. This affects the socio-economy of the surrounding routes. Hence, it is seen, as preventive maintenance of the roads will provide more feasible option in term of work force and finance to the local authority. To overcome this issue, a preventive model was introduced. This was done through pavement condition assessment (PCA) where analysis was done through HDM-4. Nondestructive test and destructive test were conducted in order to provide an indicator to the road's health. This were then analyzed in HDM-4 where the result was benchmarked with maintenance standard. The scope of this research is set to PCA where DT and NDT were performed on the routes of Petaling and the output is analyzed in HDM-4. The result of this research provides a 10 years forecast maintenance budget in maintaining the roads in Petaling. This allows the local authority to perform good practice in term of maintaining the roads while at the same time helps them in forecasting their budget for the upcoming years. This research will have a strong impact on the local socio-economy as well as local road user confidence towards the authority over good practices. This research can be further expanded to other type of roads as well as highway bridges.

Failure mode and effect analysis in asset maintenance : a multiple case study in the process industry

NARCIS (Netherlands)

Braaksma, Jan; Klingenberg, W.; Veldman, J.

2013-01-01

Failure mode and effect analysis (FMEA) is an important method for designing and prioritising preventive maintenance activities and is often used as the basis for preventive maintenance planning. Although FMEA was studied extensively, most of the published work so far covers FMEA concept design.

Failure mode and effect analysis in asset maintenance: a multiple case study in the process industry

NARCIS (Netherlands)

Braaksma, Anne Johannes Jan; Klingenberg, W.; Veldman, Jasper

2013-01-01

Failure mode and effect analysis (FMEA) is an important method for designing and prioritising preventive maintenance activities and is often used as the basis for preventive maintenance planning. Although FMEA was studied extensively, most of the published work so far covers FMEA concept design.

Concepts for measuring maintenance performance and methods for analysing competing failure modes

DEFF Research Database (Denmark)

Cooke, R.; Paulsen, J.L.

1997-01-01

competing failure modes. This article examines ways to assess maintenance performance without introducing statistical assumptions, then introduces a plausible statistical model for describing the interaction of preventive and corrective maintenance, and finally illustrates these with examples from...

Model for cost economic analysis in the maintenance of distribution networks

International Nuclear Information System (INIS)

Flores, N.; Leite, O.C.; Abe, R.Y.; Violante, R.A.

1989-01-01

A methodology for evaluating the costs from aerial distribution networks maintenance is described, aiming give a tool for the planning decisions, with the purpose to keeping the system operating in equilibrium conditions between the resources invested on the preventive and corrective maintenance. (C.G.C.)

Influence of abutment type and esthetic veneering on preload maintenance of abutment screw of implant-supported crowns.

Science.gov (United States)

Delben, Juliana Aparecida; Barão, Valentim Adelino Ricardo; Dos Santos, Paulo Henrique; Assunção, Wirley Gonçalves

2014-02-01

The effect of veneering materials on screw joint stability remains inconclusive. Thus, this study evaluated the preload maintenance of abutment screws of single crowns fabricated with different abutments and veneering materials. Sixty crowns were divided into five groups (n = 12): UCLA abutment in gold alloy with ceramic (group GC) and resin (group GR) veneering, UCLA abutment in titanium with ceramic (group TiC) and resin (group TiR) veneering, and zirconia abutment with ceramic veneering (group ZiC). Abutment screws made of gold were used with a 35 Ncm insertion torque. Detorque measurements were obtained initially and after mechanical cycling. Data were analyzed by ANOVA and Fisher's exact test at a significance level of 5%. For the initial detorque means (in Ncm), group TiC (21.4 ± 1.78) exhibited statistically lower torque maintenance than groups GC (23.9 ± 0.91), GR (24.1 ± 1.34), and TiR (23.2 ± 1.33) (p abutment type and veneering material. More irregular surfaces in the hexagon area of the castable abutments were observed. The superiority of any veneering material concerning preload maintenance was not established. © 2013 by the American College of Prosthodontists.

Nuclear instrument maintenance - problems, solutions, and obstacles

International Nuclear Information System (INIS)

Vuister, P.H.

1983-01-01

In 200 laboratories of South-East Asia, Latin America and Africa a survey was made of the state of instrumentation for nuclear medicine. The principal cause of failures and defects was inadequate quality control and preventive maintenance. On the basis of the survey coordinated research programs were compiled for the maintenance of nuclear instruments. The four principal points of the programs are: to safeguard quality and stable electric power supplies for the instruments, to safeguard permanent temperature and humidity in the environment in which the equipment is operated, effective maintenance, and training of personnel. In the years 1981 and 1982, 14 local training courses were run in which emphasis was put on practicals and tests in mechanics and electronics

Excellence through maintenance mastering

International Nuclear Information System (INIS)

Lamarche, M.; Guillot, M.; Monier, M.

1987-01-01

To improve the overall availability factor of nuclear power plants you have to cut either the forced outage role and the planned outage time or you need to reduce simultaneously the failures and the efforts devoted to avoiding them. Among other results, this goal leads to a decrease in the number of real or anticipated problems. Electricite de France policy, in this matter, is to focus on decreasing the compoents' maintenance needs through a comprehensive modification program, targeted to eliminating the weak points as revealed by the operation. Thereby one may reach, for simple equipment, a nearly maintenance-free condition in which the only maintenance needed is surveillance, which provides assurance that everything is operating properly. A good example of this type of equipment is the family of static components, drums, and pipes whose corrective maintenance is almost nil when their initial condition is good

Nuclear maintenance strategy and first steps for preliminary maintenance plan of the EU HCLL & HCPB Test Blanket Systems

Energy Technology Data Exchange (ETDEWEB)

Galabert, Jose, E-mail: jose.galabert@f4e.europa.eu [F4E Fusion for Energy, EU Domestic Agency, c/Josep Pla, 2. B3, 08019, Barcelona (Spain); Hopper, Dave [AMEC Foster Wheeler, Faraday Street, Birchwood Park, WA3 6GN (United Kingdom); Neviere, Jean-Cristophe [ITER Organization, Route de Vinon-sur-Verdon, CS 90046, 13067, St. Paul Lez Durance Cedex (France); Nodwell, David [CCFE, Culham Science Centre, Abingdon, OX14 3DB, Oxfordshire (United Kingdom); Pascal, Romain [ITER Organization, Route de Vinon-sur-Verdon, CS 90046, 13067, St. Paul Lez Durance Cedex (France); Poitevin, Yves; Ricapito, Italo [F4E Fusion for Energy, EU Domestic Agency, c/Josep Pla, 2. B3, 08019, Barcelona (Spain); White, Gareth [AMEC Foster Wheeler, Faraday Street, Birchwood Park, WA3 6GN (United Kingdom)

2017-03-15

Highlights: • Nuclear maintenance strategy for the two European (EU) Test Blanket Systems (TBS): i/. Helium Cooled Lead Lithium (HCLL) and ii/. Helium Cooled Pebble Bed (HCPB). • Preliminary identification of maintenance tasks for most relevant components of the EU HCLL & HCPB TBS. • Preliminary feasibility analysis for hands-on maintenance tasks of some relevant components of the European Test Blanket Systems. • Design recommendations for enhancement of the European Test Blanket Systems maintainability. - Abstract: This paper gives an overview of nuclear maintenance strategy to be followed for the European HCLL & HCPB Test Blanket Systems (TBS) to be installed in ITER. One of the several core documents to prepare in view of their licensing is their respective ‘Maintenance Plan’. This document is fundamental for ensuring sound performance and safety of the TBS during ITER’s operational phase and shall include, amongst others, relevant information on: maintenance organization, preventive and corrective maintenance task procedures, condition monitoring for key components, maintenance work planning, and a spare parts plan, just to mention some of the key topics. In compliance with the ITER Plant Maintenance policy, first steps have been taken aimed at defining nuclear maintenance strategy for some of the most relevant HCLL & HCPB TBS components, conducted by F4E in collaboration with industry. After a brief recall of maintenance strategy of the TBM Program (PBS-56), this paper analyses main features of EU HCLL & HCPB TBS maintainability and identifies, at their conceptual design phase, a preliminary list of maintenance tasks to be developed for their most representative components. In addition, the paper also presents the first nuclear maintenance studies conducted for replacement of the Q{sub 2} Getter Beds, identifying some design recommendations for their sound maintainability.

Nuclear maintenance strategy and first steps for preliminary maintenance plan of the EU HCLL & HCPB Test Blanket Systems

International Nuclear Information System (INIS)

Galabert, Jose; Hopper, Dave; Neviere, Jean-Cristophe; Nodwell, David; Pascal, Romain; Poitevin, Yves; Ricapito, Italo; White, Gareth

2017-01-01

Highlights: • Nuclear maintenance strategy for the two European (EU) Test Blanket Systems (TBS): i/. Helium Cooled Lead Lithium (HCLL) and ii/. Helium Cooled Pebble Bed (HCPB). • Preliminary identification of maintenance tasks for most relevant components of the EU HCLL & HCPB TBS. • Preliminary feasibility analysis for hands-on maintenance tasks of some relevant components of the European Test Blanket Systems. • Design recommendations for enhancement of the European Test Blanket Systems maintainability. - Abstract: This paper gives an overview of nuclear maintenance strategy to be followed for the European HCLL & HCPB Test Blanket Systems (TBS) to be installed in ITER. One of the several core documents to prepare in view of their licensing is their respective ‘Maintenance Plan’. This document is fundamental for ensuring sound performance and safety of the TBS during ITER’s operational phase and shall include, amongst others, relevant information on: maintenance organization, preventive and corrective maintenance task procedures, condition monitoring for key components, maintenance work planning, and a spare parts plan, just to mention some of the key topics. In compliance with the ITER Plant Maintenance policy, first steps have been taken aimed at defining nuclear maintenance strategy for some of the most relevant HCLL & HCPB TBS components, conducted by F4E in collaboration with industry. After a brief recall of maintenance strategy of the TBM Program (PBS-56), this paper analyses main features of EU HCLL & HCPB TBS maintainability and identifies, at their conceptual design phase, a preliminary list of maintenance tasks to be developed for their most representative components. In addition, the paper also presents the first nuclear maintenance studies conducted for replacement of the Q_2 Getter Beds, identifying some design recommendations for their sound maintainability.

Towards total productive maintenance in the Eastern European mining industry

Energy Technology Data Exchange (ETDEWEB)

Buck, J.D. [Kepner-Tregoe (United Kingdom) Ltd., Windsor

1999-08-01

An European Union consultancy project was undertaken to install a `best-in-class` maintenance system for the lignite mines of Romania. The project, funded by PHARE, started with a critical analysis of the maintenance and repair systems of equipment in both the open-pit and underground mines operated by RALO (Regia Autonoma a Lignitului Octenia). This study paved the way for the introduction of a computerised maintenance system and the inception of a planned preventative maintenance scheme. A development strategy leading by a structural methodology towards predictive maintenance and total productive maintenance was drawn up and attention was given to multi-skilling, training and further facilitating activities to enable the success of the total productive maintenance strategy. An abridged version of the paper was presented at MAINTE 97, held in Birmingham, UK in 1997. 5 refs., 5 figs., 1 tab.

The CIDEM project for integrating availability, operating experience and maintenance in the design of future nuclear power plants

International Nuclear Information System (INIS)

Degrave, C.; Martin-Onraet, M.

1998-01-01

To minimize the kWh cost of future nuclear plants EDF has decided to implement the CIDEM project (French acronym for Design Integrating Availability, Operating Experience and Maintenance), an analytic and systematic process for studying new projects. The first CIDEM application is centered on the future French nuclear unit construction program, known as the REP 2000 Program but the approach could be applied to other Reactor type. The CIDEM studies at the beginning, were oriented to the issues strongly impacting the availability. They have concerned: planned outages, forced outages and preventive maintenance. The studies were carried out by a team grouping engineers from the 3 EDF's Divisions (Engineering-Generation-Research), and working together in a Concurrent Engineering-Mode. This team works in close collaboration with the vendors and the German Utilities involved in the REP 2000 EPR program. The implementation of the CIDEM process constitutes for EDF a new approach to the study of the new Nuclear Power Plant projects. The studies conducted in the availability field have already highlighted a number of critical points and have made it possible to establish a series of specifications for the REP 2000/EPR project. The integration in the design process of Preventive Maintenance and Logistic Support studies will allow a better control of the maintenance cost. The competitiveness of nuclear energy greatly depends on the success of such an approach. (author)

The maintenance of nuclear medicine equipments: the stakes in the liberal sector

International Nuclear Information System (INIS)

Fauchet, M.; Chambon, T.; Tellier, P.

1994-01-01

Maintenance of nuclear medicine installations is an obligation in the private sector (preventive maintenance to be sure of the detectors quality and of the associated software and hardware, corrective maintenance to be sure of the results quality and of the installations profitability). They must be negotiated at the time of the installations choice and added to the total cost of the equipment. Gamma cameras are chosen for illustrating these maintenance problems. (A.B.). 5 refs., 7 figs

A probabilistic computational framework for bridge network optimal maintenance scheduling

International Nuclear Information System (INIS)

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.

A Novel Short-Term Maintenance Strategy for Power Transmission and Transformation Equipment Based on Risk-Cost-Analysis

Directory of Open Access Journals (Sweden)

Hang Yang

2017-11-01

Full Text Available Current studies on preventive condition-based maintenance of power transmission and transformation equipment mainly focus on mid-term or long-term maintenance, and cannot meet the requirements of short-term especially temporary maintenance. In order to solve the defects of the present preventive maintenance strategies, according to the engineering application and based on risk-cost analysis, a short-term maintenance strategy is proposed in this manuscript. For the equipment working in bad health condition, its active maintenance costs and operation risk costs are evaluated, respectively. Then the latest maintenance time is calculated in accordance with the principle that its operation risk costs are no higher than active maintenance costs. Utilizing the latest maintenance time, the best maintenance time is calculated by setting the maximum relative earnings of postponing maintenance as the target, which provides the operation staffs with comprehensive maintenance-decision support. In the end, different cases on the IEEE 24-bus system are simulated. The effectiveness and advantages of the proposed strategy are demonstrated by the simulation results.

A summary of maintenance policies for a finite interval

International Nuclear Information System (INIS)

Nakagawa, T.; Mizutani, S.

2009-01-01

It would be an important problem to consider practically some maintenance policies for a finite time span, because the working times of most units are finite in actual fields. This paper converts the usual maintenance models to finite maintenance models. It is more difficult to study theoretically optimal policies for a finite time span than those for an infinite time span. Three usual models of periodic replacement with minimal repair, block replacement and simple replacement are transformed to finite replacement models. Further, optimal periodic and sequential policies for an imperfect preventive maintenance and an inspection model for a finite time span are considered. Optimal policies for each model are analytically derived and are numerically computed

Analysis on the gamma dose distribution by major corrosion products during preventive maintenance period in nuclear power plant

International Nuclear Information System (INIS)

Ha, Wi Ho

2006-02-01

The information on dose distribution inside the containment building is an essential requirement to make a reduction of radiation exposure as well as effective operation and design of nuclear power plant. After reactor shutdown, radiation exposure to workers mainly occurs during preventive maintenance period due to inspection or repair works of major components. During that period, gamma doses are induced by major corrosion products in the primary coolant system. The radiation exposure to workers has been assessed by using the measurements. The measurements are, of course, a basic and reliable assessment. But the measurement has defect such as limitation of detecting area. In order to improve the defect of the measurements, system for assessment of gamma dose distribution during preventive maintenance period by using computational code was suggested in this study. First, activity of major corrosion products was calculated by using modified CRUDSIM code. Original CRUDSIM code was modified to add evaluation of other major corrosion products besides cobalt isotopes. Modeling of containment building for YGN Unit 3 was then performed. Gamma dose distribution by major corrosion products inside the containment building was calculated by using MCNPX code. Finally, the calculations were mapped for whole space inside the containment building and were compared with the measurements. As a result of this study, the defect of the measurement are supplemented by using computational calculation system, and it is expected that workers can make an effective work plan through providing dose distribution inside the containment building in advance. In addition, this study can be applied to technology development to make an effective containment shielding design of the next generation reactor as well as an improvement of the safety for workers in nuclear power plant

Optimisation of distributed maintenance: Modelling and application to the multi-factory production

Energy Technology Data Exchange (ETDEWEB)

Simeu-Abazi, Zineb, E-mail: Zineb.Simeu-Abazi@g-scop.inpg.fr [Laboratory G-SCOP, 46 Avenue Felix Viallet, 38031 Grenoble Cedex 1 (France); Ahmad, Alali Alhouaij [Laboratory G-SCOP, 46 Avenue Felix Viallet, 38031 Grenoble Cedex 1 (France)

2011-11-15

This paper concerns the modelling and the cost evaluation of maintenance activities in a distributed context. In this work we study the particular case where the maintenance activities are executed by two workshops: a central maintenance workshop (CMW) and a mobile maintenance workshop (MMW). The CMW concerns the repairing process for the corrective maintenance and the MMW executes all preventive maintenance in several factories according to a defined scheduling. The aim is to take into account the resources (spare parts in the MMW) and maintenance actions for a given operating budget. A modular approach for modelling a multi-site structure is proposed to achieve the aim of improving the availability of facilities on production sites while minimising the cost of maintenance.

Policy for equipment’s leasing period extension with minimum cost of maintenance

Science.gov (United States)

Lestari, C.; Kurniati, N.

2018-04-01

The cost structure for equipment investment including purchase cost and maintenance cost is getting more expensive. The company considers to lease the equipment instead of purchase it under a contractual agreement. Offering to extend the lease period, following to the base lease period, will provide more benefits for both the lessor (owner) and the lessee (user). Whenever the lease period extension offered at the beginning of the contract, there are some risks in finance e.g. uncertainty of the equipment performance and lessor responsibility. Therefore, this research attempts to model the optimal maintenance policy for lease period extension offered at the end of the contract. Minimal repair is performed to rectify a failed equipment, while imperfect preventive maintenance is conducted to improve the operational state of the equipment when reaches a certain control limit to avoid failures. The mathematical model is constructed to determine the optimal control limit, the number and degree of preventive maintenance, and the multiplication number of the lease period extension. Finally, numerical examples are given to illustrate the influences of the optimal length of the extended lease and the maintenance policy to minimize the maintenance cost.

Obesity Prevention and Weight Maintenance After Loss.

Science.gov (United States)

German, Alexander James

2016-09-01

Obesity is one of the most prevalent medical diseases in pets. Outcomes are often disappointing; many animals either fail to reach target weight or regain weight. This article discusses managing obesity, focusing on prevention. It gives guidance on establishing monitoring programs that use regular body weight and condition assessments to identify animals at risk of inappropriate weight gain, enabling early intervention. Weight management in obese animals is a lifelong process. Regular weight and body condition monitoring are key to identifying animals that rebound early, while continuing to feed a therapeutic weight loss diet can help prevent it from happening. Copyright © 2016 Elsevier Inc. All rights reserved.

Operations and maintenance plans for the TFTR

International Nuclear Information System (INIS)

Allen, H.L.; Fedor, B.J.

1978-01-01

Princeton University Plasma Physics Laboratory (PPPL) is constructing a Tokamak Fusion Test Reactor (TFTR) scheduled to begin operation for fusion research experiments in late 1981, first with hydrogen and deuterium plasmas and later, in the second phase, using tritium for high power fusion studies. This latter mode will introduce considerable complexity to operation and maintenance of the TFTR in terms of meeting requirements for tritium handling, adequate radiation shielding, and corrective and preventive maintenance procedures. In this paper we discuss plans for the installation and preoperational testing of the major subsystems of TFTR, proposed start-up and operating scenarios for the device and the system of operational control. In addition, the TFTR Maintenance Plan and related procedures for specific major maintenance tasks are described, including the use of remote handling equipment and remote manipulators. Each of these topics is addressed in terms of the current status of planning and development

Probabilistic analysis of free ways for maintenance

International Nuclear Information System (INIS)

Torres V, A.; Rivero O, J.J.

2004-01-01

The safety during the maintenance interventions is treated in limited manner and in general independent of the systems of management of the maintenance. This variable is affected by multiple technical or human factors many times subjective and difficult to quantifying, what limits the design of preventive plans. However, some factors constitute common points: the isolation configurations during the free ways (bank drafts in the oil industry) and the human errors associated to their violation. This characteristic allowed to develop the analysis of such situations through the methodology of fault trees that it links faults of teams and human errors cohesively. The methodology has been automated inside the MOSEG Win Ver 1.0 code and the same one can embrace from the analysis of a particular situation of free way until that of a complete strategy of maintenance from the point of view of the safety of the maintenance personal. (Author)

Pollution Prevention/Waste Minimization

International Nuclear Information System (INIS)

Fowler, Kimberly M.; Hyman, Marvin H.

2002-01-01

This chapter offers pollution prevention techniques for design, industrial process, maintenance, and environmental remediation activities. It provides examples of waste reduction, tools for identifying pollution prevention opportunities, and ways of calculating the payback or return on investment associated with the opportunities

Costs of performance based maintenance for local roads: Case study Albania

OpenAIRE

Jokanović Igor; Grujić Bojana; Zeljić Dragana; Grujić Žarko; Svilar Mila

2017-01-01

The provision and maintenance of road infrastructure is a major global business, consequently it is essential that road maintenance services are provided in the most cost effective manner. Without regular maintenance, roads can rapidly fall into disrepair, preventing realization of the longer term impacts of road improvements on development, such as increased agricultural production and growth in school enrollment, which is of particular importance for a network of local (access) roads. Inade...

Experience based reliability centered maintenance

International Nuclear Information System (INIS)

Haenninen, S.; Laakso, K.

1993-03-01

The systematic analysis and documentation of operating experiences should be included in a living NPP life management program. Failure mode and effects and maintenance effects analyses are suitable methods for analysis of the failure and corrective maintenance experiences of equipment. Combined use of the information on occurred functional failures and the decision tree logic of the reliability centered maintenance identifies applicable and effective preventive maintenance tasks of equipment in an old plant. In this study the electrical motor drives of closing and isolation valves (MOV) of TVO and Loviisa nuclear power plants were selected to serve as pilot study objects. The study was limited to valve drives having actuators manufactured by AUMA in Germany. The fault and maintenance history of MOVs from 1981 up to and including October 1991 in different safety and process systems at TVO 1 and 2 nuclear power units was at first analyzed in a systematic way. The scope of the components studied was 81 MOVs in safety-related systems and 127 other MOVs per each TVO unit. In the case of the Loviisa plant, the observation period was limited to three years, i.e. from February 1989 up to February 1992. The scope of the Loviisa 1 and 2 components studied was 44 respectively 95 MOVs. (25 refs., 22 figs., 8 tabs.)

A plant-based diet for the prevention and treatment of type 2 diabetes.

Science.gov (United States)

McMacken, Michelle; Shah, Sapana

2017-05-01

The prevalence of type 2 diabetes is rising worldwide, especially in older adults. Diet and lifestyle, particularly plant-based diets, are effective tools for type 2 diabetes prevention and management. Plant-based diets are eating patterns that emphasize legumes, whole grains, vegetables, fruits, nuts, and seeds and discourage most or all animal products. Cohort studies strongly support the role of plant-based diets, and food and nutrient components of plant-based diets, in reducing the risk of type 2 diabetes. Evidence from observational and interventional studies demonstrates the benefits of plant-based diets in treating type 2 diabetes and reducing key diabetes-related macrovascular and microvascular complications. Optimal macronutrient ratios for preventing and treating type 2 diabetes are controversial; the focus should instead be on eating patterns and actual foods. However, the evidence does suggest that the type and source of carbohydrate (unrefined versus refined), fats (monounsaturated and polyunsaturated versus saturated and trans), and protein (plant versus animal) play a major role in the prevention and management of type 2 diabetes. Multiple potential mechanisms underlie the benefits of a plant-based diet in ameliorating insulin resistance, including promotion of a healthy body weight, increases in fiber and phytonutrients, food-microbiome interactions, and decreases in saturated fat, advanced glycation endproducts, nitrosamines, and heme iron.

Operation and maintenance requirements of system design bases

International Nuclear Information System (INIS)

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

PREVENTIVE PAEDIATRICS — NEW CHALLENGES

Directory of Open Access Journals (Sweden)

A. A. Baranov

2012-01-01

Full Text Available The article takes up priority directions of preventive paediatrics concerning health formation of rising generation, organization of health care for children, decrease of morbidity, disability and mortality rate. The authors mention the importance of vaccination in control of the most common infections, base the necessity of complex rehabilitation health care system organization for disable children and need of wide spreading of developed and used in practical Russian health care types and methods of prophylaxis of rare (orphan diseases. The ways of prophylaxis, maintenance, strengthening and recovery of children’s health are suggested in this article.

Ageing nuclear plants inspection, maintenance and performance monitoring eased by Data Validation and Reconciliation (DVR) approach

International Nuclear Information System (INIS)

Quang, A. Tran; Chares, R.

2012-01-01

With the long term operation of nuclear power plants, decisions to replace or repair should be optimized from an economical, human resource and safety point of view. In that frame, the operation requires a continuous inspection and testing of systems in order to detect degradations and failures at an early stage. Nevertheless, in spite of the fact that such assiduous vigilance ensures safety, it is not optimized in terms of man power and maintenance costs. Preventive strategies show the same types of drawbacks. On top of that, these maintenance procedures rely on process measurements which accuracy, availability and reliability cannot always be ensured. The present paper introduces a new approach to the maintenance management of ageing installations and suggests a method that overcomes the actual drawbacks. The Reconciliation and Validation of data (DVR) is an advanced and innovative technology that relies on process data statistics, thermodynamic and on-site process knowledge. Benefits of real-time applications are also presented. (author)

Current status of research and development on remote maintenance for fusion components

International Nuclear Information System (INIS)

Takeda, Nobukazu; Kakudate, Satoshi; Nakahira, Masataka; Shibanuma, Kiyoshi

2008-01-01

There is a growing attention to remote maintenance of nuclear fusion reactors. Remote maintenance is planned in ITER tokamak to keep the health of in-vessel components like blankets and divertors. In this article, current status of the development in the remote maintenance equipments and methods, especially for ITER tokamak are reviewed. The newly developed vehicle type and boom type maintenance devices, manipulator, and transfer cask are illustrated. (J.P.N.)

Taipower plans to cut O and M costs [reactor maintenance management

International Nuclear Information System (INIS)

Tsui, S.J.

1989-01-01

Taipower aims to reduce operation and maintenance costs at its three BWRs, as well as the time devoted by plant personnel to O and M paper work, by ensuring that maintenance and spare-parts management is systematic and well documented. It is currently developing an on-line maintenance information system, known as the Maintenance Management Computerization System (MMCS), which can be accessed from any of Taipower's plants. MMCS is designed to be an on-line interactive multiple-user system through which the authorized user has immediate access to maintenance information. It will be used for preventive and corrective maintenance, surveillance tests, tagging, document control, instrument calibration and refuelling outage management. The system is simple to operate, using pull-down menus and standard text. (author)

Application and issues of online maintenance for equipment of nuclear power plants

International Nuclear Information System (INIS)

Higasa, Hisakazu

2011-01-01

The maintenance systems for long-term safety and repair costs reduction of equipment of nuclear power plants are stated. Planned maintenance contained the breakdown maintenance (BM) and the preventive maintenance, which consists of the time based maintenance (MBM) and the condition based maintenance (CBM). Explained are the characteristics of equipments, maintenance methods, maintenance solutions and the self-evaluation maintenance power, damage mechanism and solutions, and monitoring tools and application. Stated are the maintenance system and application of monitoring technology, periodical maintenance, application of diagnosis, vibration monitoring techniques, decision of vibration monitoring, and application of monitoring techniques for improvement of maintenance. Illustrated are realization of planned maintenance by reorganization of maintenance, a trend of maintenance of equipments, table of classified maintenance systems, change of maintenance program, maintenance data and investigation of damage mechanism, examples of self-evaluation maintenance power, examples of analysis of damage of parts of equipments, evaluation of rotating machines by vibration method, examples of results of diagnosis of bearing of rotating machines, online maintenance system of Asahi Kasei Engineering Corporation, degradation pattern of pomp, estimation of lifetime by total vibration and vibration on acceleration, and improvement of equipments. (S.Y.)

Study protocol for a randomized controlled trial comparing mindfulness-based cognitive therapy with maintenance anti-depressant treatment in the prevention of depressive relapse/recurrence: the PREVENT trial

Directory of Open Access Journals (Sweden)

Hayes Rachel

2010-10-01

Full Text Available Abstract Background Depression is a common and distressing mental health problem that is responsible for significant individual disability and cost to society. Medication and psychological therapies are effective for treating depression and maintenance anti-depressants (m-ADM can prevent relapse. However, individuals with depression often express a wish for psychological help that can help them recover from depression in the long-term. We need to develop psychological therapies that prevent depressive relapse/recurrence. A recently developed treatment, Mindfulness-based Cognitive Therapy (MBCT, see http://www.mbct.co.uk shows potential as a brief group programme for people with recurring depression. In two studies it has been shown to halve the rates of depression recurring compared to usual care. This trial asks the policy research question, is MBCT superior to m-ADM in terms of: a primary outcome of preventing depressive relapse/recurrence over 24 months; and, secondary outcomes of (a depression free days, (b residual depressive symptoms, (c antidepressant (ADM usage, (d psychiatric and medical co-morbidity, (e quality of life, and (f cost effectiveness? An explanatory research question asks is an increase in mindfulness skills the key mechanism of change? Methods/Design The design is a single blind, parallel RCT examining MBCT vs. m-ADM with an embedded process study. To answer the main policy research question the proposed trial compares MBCT plus ADM-tapering with m-ADM for patients with recurrent depression. Four hundred and twenty patients with recurrent major depressive disorder in full or partial remission will be recruited through primary care. Depressive relapse/recurrence over two years is the primary outcome variable. The explanatory question will be addressed in two mutually informative ways: quantitative measurement of potential mediating variables pre/post-treatment and a qualitative study of service users' views and experiences

Behaviour, the key factor for sports injury prevention.

Science.gov (United States)

Verhagen, Evert A L M; van Stralen, Maartje M; van Mechelen, Willem

2010-11-01

Safety in sports and physical activity is an important prerequisite for continuing participation in sports, as well as for maintenance of a healthy physically active lifestyle. For this reason, prevention, reduction and control of sports injuries are important goals for society as a whole. Recent advances in sports medicine discuss the need for research on real-life injury prevention. Such views call for a more behavioural approach when it comes to actual sports injury prevention. Nevertheless, the role of behaviour in sports injury prevention remains under-researched. In order to push the field of sports injury prevention forward, this article provides an overview of the relationship between behaviour and sports injury risk. Different types of behaviour relate to injury risk factors and injury mechanisms. Behaviour that influences risk factors and injury mechanisms is not confined only to the athlete. Various types of behaviour by, for example, the coach, referee, physical therapist or sports associations, also influence risk factors and injury mechanisms. In addition, multiple behaviours often act together. Some types of behaviour may directly affect injury risk and are by definition a risk factor. Other behaviours may only affect risk factors and injury mechanisms, and influence injury risk indirectly. Recent ideas on injury prevention that call for studies on real-life injury prevention still rely heavily on preventive measures that are established through efficacy research. A serious limitation in such an approach is that one expects that proven preventive measures will be adopted if the determinants and influences of sports safety behaviours are understood. Therefore, if one truly wants to prevent sports injuries in a real-life situation, a broader research focus is needed. In trying to do so, we need to look at lessons learned from other fields of injury prevention research.

Optimizing Maintenance Planning in the Production Industry Using the Markovian Approach

Directory of Open Access Journals (Sweden)

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.

Maintenance risk management in Dayabay nuclear power plant

International Nuclear Information System (INIS)

He Xuhong; Tong Jiejuan

2005-01-01

The importance of proper maintenance to safe and reliable nuclear plant operation has long been recognized by the nuclear utility and regulatory body. This paper presents a process of maintenance risk management developed for a Chinese Nuclear Power Plant (NPP). The process includes three phases: (I) long term maintenance plan risk management, (II) monthly maintenance plan risk management, and (III) detailed risk management for high risk configuration. A risk matrix is developed for phase I whose purpose is to provide a rough guide for risk management in the making of the annual maintenance plan. For Phase II and Phase III, a software tool named Maintenance- Risk-Monitor is developed based on the internal initiating event, level 1 PSA model. The results of Phase II are the risk information of the all plant configurations caused by the unavailability of the components included the monthly maintenance plan. When the increase of core damage frequency (CDF) or the incremental core damage probability (ICDP) of a configuration is higher than the corresponding thresholds, Phase III is needed for this high risk configuration to get the useful information such as risk-importance components, human actions and initial events, from which appropriate preventive measurements could be derived. It is hoped that the provided process of maintenance risk management, together with the developed software tool, could facilitate the maintenance activities in the NPPs of China. (authors)

Development of Tokai reprocessing plant maintenance support system (TORMASS) in the Tokai reprocessing plant

International Nuclear Information System (INIS)

Shimizu, Kazuyuki; Tomita, Tsuneo; Sakai, Katsumi

2008-01-01

The maintenance work of many equipments such as mechanical, electrical and instrumentations installed in Tokai reprocessing plant has been performed more then 10,000 times per year and about 90% of maintenances were preventive work. For the maintenance management, optimization of maintenance information is required. Therefore, Tokai Reprocessing Plant Maintenance Support System (TORMASS) was developed from 1985 to 1992 as the aim of construction for suitable maintenance management system. About 24,000 equipments of specifications and about 261,000 maintenance detail were registered in this system. TORMASS has been used for the repair, inspection and replacement of equipment since 1992. (author)

Identification of IncA/C Plasmid Replication and Maintenance Genes and Development of a Plasmid Multilocus Sequence Typing Scheme.

Science.gov (United States)

Hancock, Steven J; Phan, Minh-Duy; Peters, Kate M; Forde, Brian M; Chong, Teik Min; Yin, Wai-Fong; Chan, Kok-Gan; Paterson, David L; Walsh, Timothy R; Beatson, Scott A; Schembri, Mark A

2017-02-01

Plasmids of incompatibility group A/C (IncA/C) are becoming increasingly prevalent within pathogenic Enterobacteriaceae They are associated with the dissemination of multiple clinically relevant resistance genes, including bla CMY and bla NDM Current typing methods for IncA/C plasmids offer limited resolution. In this study, we present the complete sequence of a bla NDM-1 -positive IncA/C plasmid, pMS6198A, isolated from a multidrug-resistant uropathogenic Escherichia coli strain. Hypersaturated transposon mutagenesis, coupled with transposon-directed insertion site sequencing (TraDIS), was employed to identify conserved genetic elements required for replication and maintenance of pMS6198A. Our analysis of TraDIS data identified roles for the replicon, including repA, a toxin-antitoxin system; two putative partitioning genes, parAB; and a putative gene, 053 Construction of mini-IncA/C plasmids and examination of their stability within E. coli confirmed that the region encompassing 053 contributes to the stable maintenance of IncA/C plasmids. Subsequently, the four major maintenance genes (repA, parAB, and 053) were used to construct a new plasmid multilocus sequence typing (PMLST) scheme for IncA/C plasmids. Application of this scheme to a database of 82 IncA/C plasmids identified 11 unique sequence types (STs), with two dominant STs. The majority of bla NDM -positive plasmids examined (15/17; 88%) fall into ST1, suggesting acquisition and subsequent expansion of this bla NDM -containing plasmid lineage. The IncA/C PMLST scheme represents a standardized tool to identify, track, and analyze the dissemination of important IncA/C plasmid lineages, particularly in the context of epidemiological studies. Copyright © 2017 American Society for Microbiology.

Factors influencing the usage of different types of malaria prevention ...

African Journals Online (AJOL)

Objective: To examine factors which influence the use of different types of malaria prevention ... risk areas, religion, education and income influenced ITN usage, whereas only age, malaria .... the uptake of IPTp given that the person would not.

A human factors approach to effective maintenance

International Nuclear Information System (INIS)

Penington, J.; Shakeri, S.

2006-01-01

Traditionally in the field of Human Factors within the nuclear industry, the focus has been to identify the potential for human errors in operating tasks, and develop strategies to prevent their occurrence, provide recovery mechanisms, and mitigate the consequences of error as appropriate. Past experience has demonstrated however a significant number of human errors within the nuclear industry occur during maintenance tasks. It is for this reason, and the fact that our nuclear power plants are ageing and increasingly in need of maintenance, that the industry must pay more attention to maintenance tasks. The purpose of this paper is to present a framework for effective maintenance programs, and based upon this framework discuss an approach (an audit tool) that can be used to both design such a program, and to assess existing programs. In addition, this tool can form the basis of cost benefit decisions relating to priorities for improvements to existing programs. (author)

Optimisation oriented lean six sigma development for maintenance management in service sector

OpenAIRE

Alsubaie, Barrak Hamdan

2016-01-01

This thesis was submitted for the award of Doctor of Philosophy and was awarded by Brunel University London This research deals with the optimization of preventive maintenance (PM) and process improvement for maintenance management in service sector. To stay competitive and sustain long-term profitability, process improvement methodologies have become strategically important for maintenance management in recent years. These include well-known approaches such as Total Quality Management (TQ...

Model-based fault diagnosis framework for effective predictive maintenance / B.B. Akindele

OpenAIRE

Akindele, Babatunde Babajide

2010-01-01

Predictive maintenance is a proactive maintenance strategy that is aimed at preventing the unexpected failure of equipment through condition monitoring of the health and performance of the equipment. Incessant equipment outage resulting in low availability of production facilities is a major issue in the Nigerian manufacturing environment. Improving equipment availability in Nigeria industry through institution of a full featured predictive maintenance has been suggested by many authors. T...

Field maintenance of radiation-shielding windows at HFEF

International Nuclear Information System (INIS)

Tobias, D.A.

1983-01-01

The achievement of excellent viewing through hot-cell shielding windows does not occur by chance. Instead, it requires a well planned and executed program of field maintenance. The lack of such a program is a major factor when a hot-cell facility has poor window viewing. At HFEF, all preventive maintenance is performed by one group of trained technical-support personnel under the immediate direction of a Systems Engineer, who has responsibility for the shielding windows. Window maintenance is prescheduled and recorded by being incorporated into the computerized Maintenance Data System (MDS). Measurements of window light transmission are scheduled annually to determine glass browning or oil cloudiness conditions within the window tank. The tank oil is sampled and chemically analyzed annually to determine the moisture content, the acidity, and the probable deterioration rate caused by irradiation

Maintenance Energy Requirements of Double-Muscled Belgian Blue Beef Cows

OpenAIRE

Fiems, Leo O.; De Boever, Johan L.; Vanacker, José M.; De Campeneere, Sam

2015-01-01

Simple Summary Double-muscled Belgian Blue animals are extremely lean, characterized by a deviant muscle fiber type with more fast-glycolytic fibers, compared to non-double-muscled animals. This fiber type may result in lower maintenance energy requirements. On the other hand, lean meat animals mostly have a higher rate of protein turnover, which requires more energy for maintenance. Therefore, maintenance requirements of Belgian Blue cows were investigated based on a zero body weight gain. T...

The application and practice of predictive maintenance at CANDU equipment management

International Nuclear Information System (INIS)

Yu Guangting

2014-01-01

The equipment in Qinshan CANDU unit is characterized by large number and complex structure. Some equipment failure has no relation with the operation time, it is impossible to avoid the failure of these equipment only by periodical maintenance. To improve the equipment reliability, increase the equipment usability and decrease the maintenance cost, for important equipment related to nuclear safety and generating electricity, it is required to perform condition monitoring and the predictive maintenance (PdM). According to different characteristics of equipment, it is required to use suitable equipment condition monitoring method, content and frequency. In this way, some potential equipment failure can be found, preventive maintenance can be arranged in advance, and equipment maintenance management can be optimized. (author)

Study on Maintenance Practices for School Buildings in Terengganu and Kedah, Malaysia

Directory of Open Access Journals (Sweden)

Mohammad Ropi R.

2014-03-01

Full Text Available Malaysia initiated talks on building maintenance in 1971 during the Second Malaysia Plan of 1971-1975. Later, the government introduced the Building and Common Property (Maintenance and Management Act, 2007 to provide proper maintenance and management of buildings. School buildings are one of the important facilities for basic knowledge in everyday life. Accordingly, the maintenance of school buildings, which serve staff and students, needs considerable attention as effective maintenance protects capital investment, ensures the health and safety of the children, and supports educational performance. Based on a combination of literature survey and questionnaire appraisal, this study evaluates the maintenance practices in designated schools in Malaysia. Overall, the study showed that most of the school buildings do not possess their own maintenance management practices. Moreover, no preventive or planned maintenance was observed, and only emergency maintenance was applied when necessary. The study recommends the implementation of planned maintenance practices, which will be more effective than unplanned maintenance, mostly because of the reduction in repair costs.

Development of support system for maintenance and administration of reprocessing plant equipment

International Nuclear Information System (INIS)

Iwasaki, Syogo; Taniguchi, Takayuki; Shiraishi, Yoshihiko; Isaka, Kazuo

1998-01-01

Each year, maintenance work is carried out for about 10,000 pieces of equipment, including mechanical devices, electric equipment and instruments, at the Tokai Reprocessing Plant. Ninety percent of such maintenance work is preventive maintenance. In order to manage the information about the maintenance work, a computer support system was developed between 1985 and 1992. Twenty-seven thousand pieces of equipment and 180,000 maintenance histories have already been registered in the system. The system has been used for planning inspections and replacement of equipment as well as checking their maintenance histories. Actual usage of the system has shown that some auxiliary functions need to be added. The system will therefore be improved and extended. (author)

Basic study of the plant maintenance model considering plant improvement/modification

International Nuclear Information System (INIS)

Tsumaya, Akira; Inoue, Kazuya; Mochizuki, Masahito; Wakamatsu, Hidefumi; Arai, Eiji

2007-01-01

This paper proposes a maintenance activity model that considers not only routine maintenance activity but also functional maintenance including improvement/modification. Required maintenance types are categorized, and limitation of Activity Domain Integration Diagram (ADID) proposed by ISO18435 are discussed based on framework for life cycle maintenance management of manufacturing assets. Then, we proposed extension ADID model for plant maintenance activity model considering functional improvement/modification. (author)

Determination of Pareto frontier in multi-objective maintenance optimization

International Nuclear Information System (INIS)

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

2011-01-01