An effective approach to reducing strategy space for maintenance optimisation of multistate series-parallel systems

Maintenance optimisation of series-parallel systems is a research topic of practical significance. Nevertheless, a cost-effective maintenance strategy is difficult to obtain due to the large strategy space for maintenance optimisation of such systems. The heuristic algorithm is often employed to deal with this problem. However, the solution obtained by the heuristic algorithm is not always the global optimum and the algorithm itself can be very time consuming. An alternative method based on linear programming is thus developed in this paper to overcome such difficulties by reducing strategy space of maintenance optimisation. A theoretical proof is provided in the paper to verify that the proposed method is at least as effective as the existing methods for strategy space reduction. Numerical examples for maintenance optimisation of series-parallel systems having multistate components and considering both economic dependence among components and multiple-level imperfect maintenance are also presented. The simulation results confirm that the proposed method is more effective than the existing methods in removing inappropriate maintenance strategies of multistate series-parallel systems.