Spare provisioning strategy for preventively replaced systems subjected to random failure

A jointly optimal periodic replacement and spare parts provisioning strategy is discussed. This strategy is completely defined once the replacement period T, the replenishment cycle R = kT (k = 1,2, ...), and the ordering point s are determined. The optimal strategy (T*,R*,s*), if it exists, is one which minimizes the total expected cost (replenishment cost + spare parts inventory management cost) per time unit over an infinite span. A numerical algorithm is proposed to find the optimal strategy. The system lifetime distribution, the probability distribution of the demand during the lead-time and the costs associated with the replenishment and the spare parts inventory management are supposed to be known. Some numerical results are presented.