DISCRETE-TIME SPARE ORDERING POLICY WITH LEAD TIME AND DISCOUNTING

摘要

The paper considers an order-replacement model for a single-unit system in a discrete time circumstance. The expected total discounted cost over an infinite time horizon is taken as a criterion of optimality and the optimal ordering policy is obtained by minimizing it. The existence and uniqueness of the optimal ordering policy are verified under certain conditions. The model is further extended to include a negative ordering time.