Optimal condition-based maintenance policy for multi-component repairable systems with economic dependence in a finite-horizon

Industrial production entails using numerous multi-component repairable systems (MCRS), and the reliability of these systems is often affected by a varying level of degradation. To maintain the reliability of degraded systems, engineers usually perform inspections and preventive maintenance programs. Existing maintenance optimization research mainly relies on renewal theories and typically overlooks component repairability. However, incorporating component repairability makes identifying renewal cycles challenging over an infinite time horizon. Although several studies have evaluated maintenance costs within a finite time horizon, most of them applied TBM strategies or simply focused on single-component systems. Therefore, we perform maintenance modeling for MCRS within a finite time horizon. First, for MCRS with economic dependence, we propose a hybrid condition-based opportunistic maintenance (CBOM) strategy. The effect pertaining to the imperfect maintenance of a component is considered in the modeling. Second, a degradation-state space-division (DSSD) method is proposed, along with a maintenance decision model that minimizes the total cost within a finite time horizon. Finally, the optimal solution is achieved using a genetic algorithm, and a numerical example is presented to validate the proposed model.