• Title, Summary, Keyword: Maintenance Effect

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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 Revision Method of Historical Fault Data Considering Maintenance Effect to Use Proportional Aging Reduction(PAR) (PAR기법을 이용하여 유지보수 영향을 고려한 고장 데이터의 보정기법에 관한 연구)

  • Chu, Cheol-Min;Kim, Jae-Chul;Moon, Jong-Fil;Lee, Hee-Tae;Park, Chang-Ho
    • Proceedings of the KIEE Conference
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    • pp.9-11
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    • 2006
  • This paper suggests a revision method for historical fault data using Proportional Aging Reduction(PAR) to consider maintenance effect in time-varying failure rate. In order to product time-varying failure rate, the historical fault data are necessary. However, the maintenance record could be left out in historical data by spot operator's mistake. In this case, the failure rate is produced less than the average failure rate for increasing equipments' life-time by maintenance effect. Hence, it is necessary for new time-varying failure rate to extract maintenance effect from the existing fault data. In this paper, the revision method to reduce equipments' life-time, adversely using PAR among three techniques to consider maintenance effect.

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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.

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 case study on evaluating the effectiveness of maintenance policies under imperfect maintenance (시뮬레이션을 통한 불완전 유지보수하에서의 유지보수 정책의 효율성 평가에 관한 사례 연구)

  • Lee, Duk-Gyu;Lee, Hi-Sung
    • Proceedings of the KSR Conference
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    • pp.1539-1544
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    • 2008
  • There is a existing study dealing with the case that the effect of preventive maintenances to restore the door system is imperfect. When the effect of the preventive maintenance is imperfect, we need to consider the maintenance effect for making reliable and economical maintenance policies. The maintenance policies applicable for imperfect maintenance cases are considered and their effectiveness are evaluated through simulation in cases of passenger door system:PDS.

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The Effect of Job Stress Responses on Human Error (직무스트레스 반응이 인적과오에 미치는 효과)

  • An, Gwan-Yeong;Son, Yong-Seung
    • Proceedings of the Safety Management and Science Conference
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    • pp.123-133
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    • 2011
  • This paper reviewed the relationship between job stress and human error, and the moderating effect of age and maintenance type on the relationship between job stress and human error in maintenance personnel. Based on the responses from 450 maintenance personnels, the results of multiple regression analysis showed that physiological and psychological stress responses have positively related with human error. In moderating effect test, age appeared to impact on the relationship between physiological/behavioral stress and human error.

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A Study on the Effectiveness of the Depot Maintenance: Based on the Maintenance Data of K-1 Main Battle Tank Since 2010 (창정비의 실효성에 대한 고찰: K-1 전차의 2010년 이후 정비자료를 바탕으로)

  • Kim, Heongil;Park, Jaehun;Sung, Si-Il
    • Journal of Applied Reliability
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    • v.17 no.3
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    • pp.256-263
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    • 2017
  • Purpose: This article provides the efficiency test results of conducting depot maintenance. Method: ANOVA (analysis of variance) and ANCOVA (analysis of covariance) tests are conducted using data obtained from Defense Logistics Integrated Information System (DELIIS). Results: The result shows that although the effect of the depot maintenance is significant, some parts do not follow the overall effect of the depot maintenance. In order to solve the problem we provide some suggestions to be improved. Conclusion: For improving the combat readiness condition of K-1 main battle tank, the maintenance policies and regulation must be revised for the parts of the weakness. In addition, the collection way of the operation and maintenance data must be redesigned.

Parameter estimation using GA with failure data under preventive maintenance (예방 정비가 실시된 고장 자료에서의 유전 알고리즘을 이용한 모수 추정)

  • 윤영원;정일한;김종운;신주환
    • Journal of Applied Reliability
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    • v.1 no.1
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    • pp.47-54
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    • 2001
  • This paper considers the parameter estimation problem of the failure intensity function and maintenance effect in a repairable system. We propose estimation procedures for repairable systems on which preventive maintenance is performed. The failure process is modeled by a proportional age reduction model [Brown, Mahoney and Sivazlian(1983)] which is useful to model the imperfect effect of preventive maintenance. When failure and maintenance (preventive) times are given, the maximum likelihood method is used to estimate the maintenance effect and the parameters of intensity function, simultaneously We obtain the maximum likelihood estimators using a genetic algorithm. A numerical example is also presented.

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Optimal Schedules of Periodic Preventive Maintenance Model with Different PM Effect

  • Lim, Jae-Hak
    • International Journal of Reliability and Applications
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    • v.9 no.1
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    • pp.113-122
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    • 2008
  • In this paper, we consider a periodic preventive maintenance policy in which each preventive maintenance reduces the hazard rate of amount proportional to the failure intensity, which increases since the system started to operate. And the effect of preventive maintenance at each preventive maintenance epoch is different. The expected cost rate per unit time for the proposed model is obtained. We discuss the optimal number N of the periodic preventive maintenance and the optimal period x, which minimize the expected cost rate per unit time and obtain the optimal preventive maintenance schedule for given cost structures of the model. A numerical example is given for the purpose of illustrating our results when the failure time distribution is Weibull distribution.

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Optimal Preventive Maintenance Period in Complex Systems in Considering Components Reliability Characteristic (하부 구성품의 신뢰도 특성을 고려한 복합 시스템의 최적 예방정비 주기 산출)

  • Lee, Youn-Ho;Lee, Ik-Do;Lee, Dong-Woo;Sohn, Ki-Hong
    • Journal of Korean Institute of Industrial Engineers
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    • v.37 no.4
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    • pp.390-399
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    • 2011
  • Generally the life-cycle cost of complex systems composed of several sub systems or equipments such as train, aircraft weapon systems is spent much more during operation and maintenance phase than development phase. The maintenance cost for maintaining the availability and extending the life span of systems comprise a large proportion of systems operation cost. The cycle of preventive maintenance affects operation and maintenance cost a lot. In this study we introduce a way minimizing life-cycle cost of systems by calculating more reliable preventive maintenance period than the results of previous study using systems reliability data considered the reliability and failure effect ratio of sub-systems or components. We can solve the preventive maintenance period problem known as NP-Hard as quick as possible by using modified genetic algorithm than using other models introduced in previous study.