JOINT DETERMINATION OF PREVENTIVE MAINTENANCE AND SAFETY STOCKS IN ANUNRELIABLE PRODUCTION ENVIRONMENT

In this article we formulate an analytical model of preventive mainten ance and safety stock strategies in a production environment subject t o random machine breakdowns. Traditionally, preventive maintenance and safety stocks have been independently studied as two separate strateg ies for coping with machine breakdowns. Our intent is to develop a uni fied framework so that the two are jointly considered. We illustrate t he trade-off between investing in the two options. In addition, we pro vide optimality conditions under which either one or both strategies s hould be implemented to minimize the associated cost function. Specifi cally, cases with deterministic and exponential repair time distributi ons are analyzed in detail. We include numerical examples to illustrat e the determination of optimal strategies for preventive maintenance a nd safety stocks. (C) 1997 John Wiley & Sons, Inc.