A revision of the Power Approximation for computing (s, S) inventory policies is presented. The revision incorporates modifications which (1) ensure homgeneity in the units chosen to measure demand and (2) ensure the proper limiting behavior of S - s when the variance of demand is extremely...

In this paper we present a new analytic approximation for computing (s, S) policies for single items under periodic review with a set-up cost, linear holding and shortage costs, fixed replenishment lead time, and backlogging of unfilled demand. The approximation formulae are derived by using...