Finding optimal policies in the (S - 1, S ) lost sales inventory model with multiple demand classes

This paper examines the algorithms proposed in the literature for finding good critical level policies in the (S-1,S) lost sales inventory model with multiple demand classes. Our main result is that we establish guaranteed optimality for two of these algorithms. This result is extended to different resupply assumptions, such as a single server queue. As a corollary, we provide an alternative proof of the optimality of critical level policies among the class of all policies.