An opportunistic maintenance model for multi-component systems experiencing shocks

Abstract

In various industrial fields, systems are often exposed to external or internal shocks, which can significantly affect their performance. This study proposes an opportunistic age-based preventive maintenance (PM) strategy for a multi-component coherent system whose components are exposed to fatal shocks. At the system’s initiation, a PM is scheduled at a set time $T_p$ . The system is subject to occasional fatal shocks, arriving in a random pattern resembling a counting process. If the system fails before $T_p$ , it will be restored to a new state by replacing the failed components and repairing the operating components to an “as good as new” state. If the system is functioning at time $T_p$ , the number of failed components is checked to decide whether the system should be replaced or allowed to continue operating. If the number of failed components at $T_p$ is less than a threshold $m$ , the PM time $T_p$ is postponed to a new PM time $T_N$ and the system continues operating in the interval $(T_p,T_N)$ . Otherwise, a PM action is performed on the entire system by replacing the failed components and repairing the operating components to an “as good as new” state. Under this scenario, we integrate a cost function based on various cost parameters to determine the optimal values of decision variables $T_p$ , $T_N$ , and $m$ . In the particular case that the process of component failures is a non-homogeneous Poisson process, we examine the effectiveness of the proposed model by analyzing some examples of coherent systems using graphical and numerical methods .