Optimization of periodic preventive maintenance policy following the expiration of two-dimensional warranty

• Published in: Reliability engineering & system safety Vol. 170; pp. 1 - 9
• Main Authors: Park, Minjae, Jung, Ki Mun, Park, Dong Ho
• Format: Journal Article
• Language: English
• Published: Barking Elsevier Ltd 01.02.2018; Elsevier BV
• Subjects: Cost model; Cost structure; Customer's perspective; Expiration; Failure time; Field data; Life cycle engineering; Life cycles; Maintenance costs; Mathematical models; Objective function; Optimization; Preventive maintenance; Reliability engineering; Repair; Repair time; Strategy; Studies; Total warranty cost; Failure time; Customer's perspective; Cost model; Field data; Total warranty cost
• ISSN: 0951-8320; 1879-0836
• DOI: 10.1016/j.ress.2017.10.009

•This paper deals with the optimal preventive maintenance policy.•Optimal preventive maintenance cycle is determined by minimizing the cost rate.•Optimal post warranty periodic preventive maintenance strategy is developed for user.•Free and pro-rata replacement and minimal repair are considered upon system failure. This paper considers an optimal periodic preventive maintenance policy after the expiration of two-dimensional warranty. During the two-dimensional warranty period, both renewal warranty and nonrenewal warranty are considered and a repair time threshold is pre-specified so that the failed system is either minimally repaired or is replaced depending on whether the length of repair time exceeds the repair time threshold or not. After the warranty expires, the system undergoes the preventive maintenance periodically a fixed number of times by the user to prolong the life of the system and then the system is replaced preventively by a new one. In this study, we develop an optimal post-warranty periodic preventive maintenance strategy by minimizing the expected cost rate incurred during the life cycle of the system. From the user's perspective, the system is maintained free of charge or with prorated charge on the failed system during the warranty period. Once the warranty expires, the maintenance cost of the system is entirely charged to the user. Subject to such a cost structure, we derive the formula to evaluate the expected cost rate, which is used as an objective function for the optimality. The main goal of this paper is to determine an optimal preventive maintenance cycle after the warranty expires and thus to propose an optimal post-warranty strategy for the user. The effect of several parameters on the optimal strategy is also investigated numerically in this study. For the purpose of illustration of our proposed model, we present and discuss some numerical examples.