The availability model and parameters estimation method for the delay time model with imperfect maintenance at inspection

The delay time model (DTM) is widely used to model the two-stage failure process and is helpful for developing cost-effective inspection/maintenance plans. Imperfect maintenance is common in practice, but seldom considered in DTM. An improved DTM with imperfect maintenance at inspection has been developed based on the assumption of imperfect inspection maintenance and perfect failure maintenance. The model of the long-run availability for the improved DTM is established. Parameters estimation method and the test for goodness of fit method are given. Numerical simulations are performed to study the influence of imperfect maintenance on the long-run availability and to validate the credibility of the parameters estimation method. The results show that imperfect maintenance will decrease the long-run availability. The existence of the optimal inspection interval regarding the maximum long-run availability is tightly related to the improvement factor, which denotes the maintenance effect. The parameters estimation method proves credible. The maximum likelihood estimations of the reliability parameters can be easily achieved by the Genetic Algorithms (GAs) searching tool.

[1]  A. H. Christer,et al.  Delay Time Models of Industrial Inspection Maintenance Problems , 1984 .

[2]  Wenbin Wang.  A two-stage prognosis model in condition based maintenance , 2007, Eur. J. Oper. Res..

[3]  A. H. Christer,et al.  The delay-time modelling of preventive maintenance of plant given limited PM data and selective repair at PM , 1998 .

[4]  T. Nakagawa.  Sequential imperfect preventive maintenance policies , 1988 .

[5]  H. Pham,et al.  Invited reviewImperfect maintenance , 1996 .

[6]  Ian Jenkinson,et al.  Methodology of using delay-time analysis for a manufacturing industry , 2009, Reliab. Eng. Syst. Saf..

[7]  Xu Congmin.  Delay Time Model Based on Imperfect Maintenance , 2009 .

[8]  N. Harnpornchai,et al.  Determination of point of maximum likelihood in failure domain using genetic algorithms , 2006 .

[9]  Rose Baker,et al.  Estimating the delay-time distribution of faults in repairable machinery from failure data , 1991 .

[10]  Chang-Hoon Lie,et al.  Estimating parameters of intensity function and maintenance effect for repairable unit , 1996 .

[11]  M. Kijima.  SOME RESULTS FOR REPAIRABLE SYSTEMS WITH GENERAL REPAIR , 1989 .

[12]  A. H. Christer,et al.  A data deficiency based parameter estimating problem and case study in delay time PM modeling , 2000 .

[13]  Terje Aven,et al.  A delay-time model with safety constraint , 2009, Reliab. Eng. Syst. Saf..

[14]  Wenbin Wang,et al.  A multi-component and multi-failure mode inspection model based on the delay time concept , 2010, Reliab. Eng. Syst. Saf..

[15]  Xiaojun Zhou,et al.  Reliability-centered predictive maintenance scheduling for a continuously monitored system subject to degradation , 2007, Reliab. Eng. Syst. Saf..

[16]  Sebastian Martorell,et al.  Age-dependent reliability model considering effects of maintenance and working conditions , 1999 .

[17]  V. Jayabalan,et al.  Cost optimization of maintenance scheduling for a system with assured reliability , 1992 .