Joint Optimization of Condition-Based Preventive Maintenance and Spare Ordering Policy

Spare provision under preventive maintenance can be an effective way to reduce operating costs. A joint strategy of stock provision and condition-based preventive maintenance is considered. Continuous review ordering policy (s,S) is combined with an inspection period for condition-based preventive maintenance. With a form (T,s,S), the joint strategy is evaluated by costs associated with maintenance and inventory. A general approach to integrating simulation with GA is proposed to search optimal joint strategy, where performance measures for specified strategy are obtained by simulation and then optimal values are searched by GA. Numerical results of an illustrative example for liquid-floated gyros indicate that the joint strategies outperform separate optimization of maintenance and spare provisioning policies when total system cost is to be minimized.