Inventory control policy for repair parts

The inventory control of repair parts has recently become an important subject in rationalizing logistics department. Information network systems for repair parts are being constructed. The purpose of this study is to propose a fixed interval ordering policy for repair parts of single item and clarify its effects. The proposed policy specifically takes into account the characteristic of repair part demands ocurring for corrective and preventive maintenance (CM and PM) and the predictability of PM demand. A new fixed interval ordering policy is discussed for negligible lead time in case where PM demands are predictable and thus their distributions are known from the first to the n-th period. In the analysis, it is theoretically clarified that the optimal expected inventory control cost decreases monotonously with respect to an increase in the predictable periods n for PM demand. It is shown that this policy can also be applied to a fixed interval ordering system considering lead time. Finally, some quantitative effects are examined by numerical examples. The proposed policy, based on the stratification of CM and PM demands and the wide-range prediction of PM demand, is considered to be effective in repair parts inventory control under information network.