Jointly Optimal Block-Replacement and Spare Provisioning Policy

This paper deals with the problem of finding a jointly optimal, block preventive replacement and spare provisioning policy for a system consisting of several like equipments. It studies the effect of inventory of spares on the optimal block replacement interval. For a single period replacement model, the jointly optimal preventive replacement interval is appreciably different from the corresponding optimal preventive replacement interval where only the replacement related costs are considered. For a multiperiod replacement model, the jointly optimal preventive replacement interval decreases from its single period optimal interval as the multiplicity of the period increases. This shows that a trade-off exists between the replacement related costs and the inventory related costs. Therefore, we get a replacement interval which is much lower than the optimal replacement interval in a single period model. There exists a finite optimal interval between two inventory replenishments not necessarily equal to the basic preventive replacement interval.