Optimizing spare inventory under group maintenance policy

A simulation model for joint optimization of GM and spare part inventory control under infinite horizon is presented through analyzing the characteristic of spare part demand of a system under group maintenance (GM) policy. In this model, maintenance activities of GM and spare supply are simulated using Monte Carlo method, by which costs of repair, spare inventory, and loss of system downtime induced by lack of spare are calculated. Then, expected total cost per unit time can be obtained by simulating for a number of periods. The preventive replacement interval and the stock level are optimized by minimizing the total cost per unit time. Matlab is utilized to gain the numerical solution of the model, and a sensitivity analysis of model has been done.