A replacement model for repairable deteriorating system

This paper studies a simple and general replacement model for a repairable deteriorating system, in which the successive survival times of the system form a process with non-increasing means, whereas the consecutive repair times after failure constitute a process with non-decreasing means, the system is replaced at the time of Nth failure after its installation or last replacement. Based on the long-run expected average cost per unit time, it determines the optimal replacement policy N* and the minimum of the long-run expected average cost, explicitly, and discusses the properties of the optimal policy N*. As an application the paper applies these results to the geometric process model.