Technical Note—Comparison between Two Dynamic Perishable Inventory Models

Two apparently different inventory models for describing optimal ordering policies for a fixed life commodity have been developed by Fries and Nahmias. This note considers the relationship between these models. Our main result is that the optimal policies for Fries' model and a discounted version of Nahmias' are identical when the remaining number of periods in the horizon exceeds the product lifetime in periods. We also discuss the relevance of these results to the computation of an approximate critical number policy developed elsewhere.