Maintenance Optimization for Dependent Two-Unit Systems Considering Stochastic Degradation and Imperfect Maintenance

Modeling on complex multi-component systems and seek the maintenance optimization have been widely investigated in recent years. In this paper, we propose a maintenance optimization policy that is applicable to dependent two-unit systems. The degradation model is based on a bivariate Wiener process. We simultaneously consider the three maintenance actions including doing nothing, imperfect repair and replacement, and implement the modeling of imperfect repair by introducing the degradation ratio that follows the beta distribution. Moreover, we solve the optimal maintenance problem of infinite horizons using the typical MDP method in sequential decision making, and give its structural properties and value iteration method. A numerical example is then demonstrated to illustrate the algorithm's viability and to investigate the model's properties.