Quality driven maintenance policies for a deteriorating system subject to non-self-announcing failures

Abstract

In this study, we develop condition-based maintenance policies for a multi-state system subject to continuous-time Markovian deterioration that can result in non-self-announcing degradation including failure. Periodic inspections reveal the true state of the system; good, medium, poor, or failed. Upon receiving this piece of information, one of do-nothing, minor repair, major repair, fix repair, or replace maintenance actions is taken. On one hand, the system brings monetary rewards commensurate with system state-different rewards are earned per unit time spent in different states. On the other hand, quality loss that results from degraded system state is converted into monetary units-inspection and maintenance costs. Therefore, our objective is to determine the optimum inspection period and the corresponding maintenance policy that maximizes the expected long-run profit rate. We provide numerical examples to conduct sensitivity of the optimum inspection period and policy to system parameters, and to present the practical utility of our results.