• Title, Summary, Keyword: Perfect Maintenance

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Imperfect Preventive Maintenance Plan of Generation Unit Using Quasi-renewal Theory (Quasi-renewal 이론을 이용한 발전설비의 불완전한 유지보수 예방정비 계획)

  • Kim, Hyung-Jun;Byun, Yoong-Tae;Kim, Jin-O;Lee, Jun-Kyong
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.57 no.5
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    • pp.735-740
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    • 2008
  • Recently, the research of PM (Preventive Maintenance) method on the RCM(Reliability-Centered Maintenance) of the system equipment is being actively advanced for a few years. For the most of the current power equipment maintenance, the state of the equipment after maintenance is assumed to be becoming 'as good as new ones' state. However, the state of the power equipment is maintained like the states of the between 'as good as new ones' and 'as bad as old ones' by imperfect maintenance that implies the life decrease of the equipment by frequent breakdown, the error of maintenance process, and so on. So, the Maintenance method considering the real case has to reflect Imperfect maintenance than perfect maintenance. This paper suggests the Preventive Maintenance method by using Quasi - Renewal Theory for the gas turbine equipment as deliberating the imperfect maintenance for the real cases.

An Introductory Study on Imperfect Maintenance Effect in Rolling Stocks

  • Kim, Jong-Woon;Han, Seok-Yun;Chung, Jong-Duk
    • International Journal of Railway
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    • v.1 no.2
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    • pp.59-63
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    • 2008
  • The maintenance effect is a peculiar factor applied to repairable systems such as rolling stocks. Conventional statistical analysis for failure times takes into account one of the two following extreme assumptions, namely, the state of the system after maintenance is either as "good as new" (GAN, perfect maintenance model) or as "bad as old" (BAO, minimal maintenance model). Most of the papers concerning the stochastic behavior of railroad systems assume two types of maintenance: perfect and minimal maintenance. However, Lee, Kim & Lee (2008) analyzed the failure data of a door system in Metro EMU and the effect of preventive maintenance was imperfect. It is seen that the imperfect maintenance is of great significance in practice. This article describes how to deal with the maintenance effect in reliability studies of rolling stocks. Maintenance policies under imperfect maintenance are described and the method is proposed to evaluate their performance.

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A Study on the Characteristics of the Imperfect Maintenance Models (불완전 보전모형의 특성에 관한 연구)

  • Yi, Jin-Shik;Lyu, Jeong-Mo
    • IE interfaces
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    • v.14 no.3
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    • pp.272-285
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    • 2001
  • Proper maintenance techniques have been emphasized in recent years due to increased safety and reliability requirements of systems, increased complexity, and rising costs of material and labor. In the related literature, most studies assume that the system after cm or pm is 'as good as new'(perfect maintenance) or 'as bad as old'(minimal maintenance). But many maintenance activities may not result in these two extreme situations but in a complicated intermediate one. Therefore, perfect maintenance and minimal maintenance are not practical in many actual instances and so realistic imperfect maintenance should be modeled. For this study, various imperfect preventive maintenance models are investigated and analyzed. From the analysis of the imperfect maintenance models modeling methods and maintenance policies are arranged and presented some tables providing informations to the maintenance managers.

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Some Stochastic Properties of Imperfect Repair Model with Random Repair Time

  • Kim, Dae-Kyung;Lim, Jae-Hak
    • International Journal of Reliability and Applications
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    • v.4 no.1
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    • pp.27-40
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    • 2003
  • Maintenance models involving minimal imperfect repair frequently appear in the literature of reliability and operations research. Most of the literatures concerning the stochastic behavior of repairable systems assume that it takes negligible time to repair a failed system and so the length of repair time does not affect the maintenance strategy. It is more realistic to consider the length of repair times in developing maintenance model, however. In this paper, we consider an imperfect repair model with random repair time and investigate some stochastic properties of the number of perfect repairs and the number of minimal repairs. Also we derive the expressions for evaluating the expected numbers of perfect and minimal repairs in general and apply these formulas for certain parametric life distributions.

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An Improved Generation Maintenance Strategy Analysis in Competitive Electricity Markets Using Non-Cooperative Dynamic Game Theory (비협조 동적게임이론을 이용한 경쟁적 전력시장의 발전기 보수계획 전략 분석)

  • 김진호;박종배;김발호
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.52 no.9
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    • pp.542-549
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    • 2003
  • In this paper, a novel approach to generator maintenance scheduling strategy in competitive electricity markets based on non-cooperative dynamic game theory is presented. The main contribution of this study can be considered to develop a game-theoretic framework for analyzing strategic behaviors of generating companies (Gencos) from the standpoints of the generator maintenance-scheduling problem (GMP) game. To obtain the equilibrium solution for the GMP game, the GMP problem is formulated as a dynamic non-cooperative game with complete information. In the proposed game, the players correspond to the profit-maximizing individual Gencos, and the payoff of each player is defined as the profits from the energy market. The optimal maintenance schedule is defined by subgame perfect equilibrium of the game. Numerical results for two-Genco system by both proposed method and conventional one are used to demonstrate that 1) the proposed framework can be successfully applied in analyzing the strategic behaviors of each Genco in changed markets and 2) both methods show considerably different results in terms of market stability or system reliability. The result indicates that generator maintenance scheduling strategy is one of the crucial strategic decision-makings whereby Gencos can maximize their profits in a competitive market environment.

A study on determining imperfect preventive maintenance intervals for the doors in Metro EMU (불완전 유지보수 모형을 통한 전동차 도어장치 예방 유지보수 주기 산정에 관한 연구)

  • Lee, Duk-Gyu;Kim, Jong-Woon;Lee, Hi-Sung
    • Proceedings of the KSR Conference
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    • pp.733-741
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    • 2008
  • An important problem in reliability analysis for repairable systems is to model the maintenance effect. The most of researches have assumed two extreme cases; one is perfect maintenance and the other is minimal maintenance. However, there are many cases in real situations that the maintenance effect are between both of two extreme cases. This article deals with the problem determining the imperfect preventive maintenance intervals for the doors in Metro EMU

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A study on Determining Maintenance Intervals Considering the Maintenance Effect for the PDS in Metro EMU (전동차 승객용도어시스템의 유지보수 효과를 고려한 유지보수 주기 산정에 관한 연구)

  • Lee, Duk-Gyu;Son, Young-Jin;Lee, Hi-Sung
    • Journal of the Korean Society for Railway
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    • v.14 no.3
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    • pp.216-221
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    • 2011
  • An important problem in reliability analysis for repairable systems is to model the maintenance effect. The most of researches have assumed two extreme cases; one is perfect maintenance and the other is minimal maintenance. However, many of maintenances performed by domestic subway operators are imperfect maintenances which have the effect between both of two extreme cases. This article deals with the problem determining the imperfect preventive maintenance intervals based on failure data in units of the PDS(passenger door system) in Metro EMU. This paper deals with a case study on determining imperfect maintenance interval by using the level of maintenance effect through reliability analysis of PDS.

Preventive Maintenance Plan of Power System Unit Considering Imperfect Maintenance (불안전한 유지보수를 고려한 전력 설비의 예방 정비 계획)

  • Byeon, Yoong-Tae;Kim, Hyung-Jun;Kim, Jin-O;Kim, Hyung-Chul
    • Proceedings of the KIEE Conference
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    • pp.328-330
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    • 2007
  • Recently, the research of PM (Preventive Maintenance) method on the RCM(Reliability-Centered Maintenance) of the system equipment is being actively advanced for a few years. The state of the power equipment is maintained like the states of the between 'as good as new ones' and 'as bad as old ones' by imperfect Maintenance that implies the life decrease of the equipment by frequent breakdown, the error of maintenance process, and so on. So, the Maintenance method considering the real case has to reflect Imperfect maintenance than perfect maintenance. This paper suggests the Preventive Maintenance method by using Quasi - Renewal Theory for the gas turbine equipment as deliberating the imperfect maintenance for the real cases.

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Optimal Maintenance Policy for Fishing Vessel Equipment Using Delay Time Analysis

  • Jung, Gi-Mun;Kwon, Young-Sub;Anand Pillay;Jin Wang
    • Proceedings of the Korean Reliability Society Conference
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    • pp.329-333
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    • 2000
  • Delay time analysis is a pragmatic mathematical concept readily embraced by engineers which has been developed as a means to model maintenance decision problem. This paper considers an inspection period using delay time analysis for fishing vessel equipment. We assume that delay time distribution is Weibull and inspections are perfect. In this paper, we determine the optimal inspection period which minimize the expected downtime per unit time.

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An Optimal Preventive Maintenance Policy with General Repair : ($\theta$, m)) Maintenance Policy (일반 수리 모형에서의 최적 예방 보전 정책에 관한 연구 : ($\theta$, m) 보전 정책)

  • Hwang, Jung-Yoon;Park, You-Jin
    • Journal of the Society of Korea Industrial and Systems Engineering
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    • v.32 no.4
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    • pp.9-16
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    • 2009
  • 본 논문에서는 시스템 연령(年齡)에 의해 보전 활동의 효과를 설명하는 일반 수리(修理) 개념을 이용한 최적 보전(保全) 정책에 대한 연구를 수행하였다. 본 논문에서는 주기적인 일반 수리와 고장 시 최소 수리가 적용되는 최적 보전 정책을 고려하였다. 따라서 일반 수리에 따른 보전 정책의 비용 함수를 도출하였고 최적 보전 정책을 도출하는 알고리즘을 제시하였고 예제를 통해 알고리즘의 성능을 분석하였다. 이 연구를 통해 시스템을 운영하는데 있어서 어느 수준의 보전 정책을 적용하며 어느 정도의 기간 동안 시스템을 유지할 것인지에 대안을 제공할 수 있을 것이다.