On preventive maintenance scheduling for the systems exposed to aging and external shocks

Abstract

This paper investigates some maintenance strategies for repairable systems that are exposed to two distinct types of failure: internal failures due to aging over time and fatal external shocks arriving according to a nonhomogeneous Poisson process. When the system fails, it will be repaired, and it is assumed that the repair does not bring the system to an as-good-as-new state. Two maintenance models are developed to prevent the system from failure under the mentioned scenario. By imposing the related cost functions, we investigate the corresponding optimal policy for each model such that the expected cost rate is minimized. Some numerical examples and simulation studies are presented to demonstrate the proposed maintenance models.