Optimal (R, nQ) Policies for Serial Inventory Systems with Guaranteed Service

In this paper, serial inventory systems with Poisson external demand and fixed costs at each stock are considered and the guaranteed-service approach (GSA) is used to design their optimal echelon (R, nQ) inventory policies. The problem is decomposed into two independent sub-problems, batch size decision sub-problem and reorder point decision sub-problem, which are solved optimally by using a dynamic programming algorithm and a branch and bound algorithm, respectively. Numerical experiments on randomly generated instances demonstrate the efficiency of these algorithms.