Remaining useful life based maintenance decision making for deteriorating systems with both perfect and imperfect maintenance actions

This paper deals with a proactive condition-based maintenance (CBM) considering both perfect and imperfect maintenance actions for deteriorating systems. Perfect maintenance actions restore completely the system to the `as good as new´ state. Their related cost are however often high. Imperfect preventive maintenance restores partially the system with reduced maintenance cost. Nevertheless, the restoration quality may depend not only on the allocated maintenance cost, the system age but also on the total number of imperfect maintenance actions executed since the last replacement time of the system. The first objective of the paper is to model imperfect maintenance actions. The second objective is to propose an adaptive maintenance policy which can help to select optimally maintenance actions (perfect or imperfect actions), if needed, at each inspection time using the remaining useful life (RUL) prognosis. To illustrate the use and the advantages of the proposed maintenance policy, different sensitivity studies are analyzed and discussed through a numerical example.