A modified imperfect preventive maintenance policy considering failure replacement

This article is an extension of the periodic imperfect maintenance model in the literature. The purpose of this research is to investigate the influence on the optimal periodic maintenance policy after considering the failure replacement in the last period of preventive maintenance (PM). The specific maintenance decisions for a repairable system are: when to replace the system, when to repair the system; whether to conduct PM or keep the system operating. A partially periodic PM policy is proposed incorporating the costs of minimal repair, PM, failure replacement, and preventive replacement. The average cost rate for the proposed policy is obtained. Finally, the optimal parameters of the maintenance policy can be calculated using the cost rate function and the numerical comparisons of different policies are provided to demonstrate the effect of failure replacement.