The inventory replenishment policy for deteriorating items under permissible delay in payments

This paper explores the inventory replenishment policy for deteriorating items under permissible delay in payments. The inventory system discussed by this paper is the same as that of Shah. At first, this paper shows that the total variable cost per unit time is convex. Then, with convexity, a simple optimization procedure is developed to improve that described by Shah. Numerical examples reveal that our optimization procedure is very accurate and rapid. Moreover, it is better than that described in Shah's paper.