Abstract: The joint optimization of equipment condition based maintenance and spare parts inventory under periodic detection is carried out. For the same multi-unit system, the maintenance requirement is determined according to the deterioration state of the whole system and the spare parts inventory state, and a joint maintenance decision model with the system detection cycle, the preventive maintenance threshold and the safety stock threshold of spare parts as decision variables and the average cost rate as the target is set up. In the process of solving the model, the degenerate state space division method is used to analyze the maintenance requirements of each decision point. On the basis of the joint probability density solution of the system, the probability of maintenance combination and the spare parts inventory state is determined. Finally, the effectiveness of the optimization method is verified by an example of multi-unit system of the terminal guidance radar, and the influence of the related parameters on the model is also discussed by sensitivity analysis.

Key words: condition based maintenance, spare parts inventory, joint optimization, multi-unit system, cost rate