Preventive maintenance for a single-machine system under variable operational conditions

Abstract

It is a common industrial practice that machines work under variable operational conditions. This article develops an imperfect maintenance model for machines working under variable operational condition, assuming that the failure time distribution of machines under different operational conditions follows the accelerated failure time model. To deal with the case that the future operational conditions’ information over the planning time interval are unknown in advance, it proposes a preventive maintenance policy which is based on current hazard rate function. An example is studied, and the results are compared with the cases that the whole operational condition information is given in advance, and the influence of operational condition is not considered. The results reveal the necessity of integrating operational condition with preventive maintenance optimization. In addition, the performance of the proposed policy has been explored with different parameters of operational conditions.