Optimal selective maintenace policy for series-parallel systems operating missions of random durations

ABSTRACT This paper deals with selective maintenance of systems required to perform missions with finite breaks between consecutive missions. During breaks, maintenance actions may be performed on system's components. For each component, a list of maintenance actions is available, from minimal repair to replacement, trough imperfect maintenance. Due to limitations on maintenance resources such as time and budget, it may not be possible to perform all necessary maintenance actions. The selective maintenance problem consists then to select a subset of maintenance actions to be performed on some components to maximize the next mission reliability. In this paper, the selective maintenance problem is investigated for a series-parallel system. Missions operated by the system are considered of uncertain durations and modeled as random variables. A mathematical optimization model is then proposed where the objective is to maximize the reliability of executing the next mission, taking into account both budget and time maintenance constraints. A numerical example is then provided and discussed. The results obtained allow to show the benefit of considering the stochasticity of missions' durations.