Optimization of spare parts in a multilevel maintenance system

This paper examines the techniques and models for allocation of an optimum number of spare parts and modules at different levels of maintenance of a hierachical structure, in order to maximize system availability and minimize the costs and delay supply downtime. Computer programmes have been developed for calculating the optimum spares allocation for two and three maintenance levels. The approach to calculate spare parts allocation has been generalized by introducing repairable-parts modules into the model. A numerical example illustrates the influence of the maintenance policy on the efficiency of the maintenance system.