The effect of deterioration on spare parts holding

Numerous mathematical models and software solutions have been developed to optimize spare parts (components) inventory based on the cost of holding versus the cost of downtime-with allowances for repairable and non-repairable components. Louit's[1] model optimized spare parts selection for both repairable and non-repairable slow-moving spare parts and included several case studies but did not address how shelf-life affected the spare parts requirements. The model developed in this paper addresses the effects of spare parts shelf-life on the optimization of spare parts selection. Certain conditions exacerbate the deterioration of spare parts, thereby affecting the reliability of the supported system. This is especially evident in non-repairable components that are stored for extended periods.