Opportunistic maintenance optimization of a two-unit system with different unit failure patterns

To investigate the optimal policy of continuously deteriorating system with economical dependence, a kind of improved opportunistic maintenance policy is presented in this paper. This system is composed of two kinds of units, which are subjected to the deterioration failure described by Gamma process and the Poisson failure respectively. The maintenance mode and corresponding control threshold are determined by the analysis of failure rules of system units. Since the optimal policy for multi-unit system should not limit itself to a simple juxtaposition of the mono-unit models considering the economical dependence, the opportunistic policy is used to coordinate the maintenance of the two kinds of units and minimize the long-run maintenance cost of the system. Finally, a numerical example is put forward to illustrate the implementation of the model and iteration algorithm.