Multiechelon (R, S) Inventory Model*
研究了两层级库存系统在随机需求下的最优库存策略，提出了确定各层级最优订货水平的数学模型和两种简单算法，并通过仿真验证。
Most studies in multiechelon inventory systems have concentrated on understanding the specific aspects of a system's behavior. The problem of optimal policy computation has largely been ignored. In this paper, we investigate a two‐echelon inventory system experiencing stochastic demand and a pull system of inventory allocation. Both echelons use an order‐up‐to‐level type control policy. A mathematical model is developed to determine the optimal order level at all echelons and validated through simulation. Two simple algorithms to locate the optimum solution are presented. The use of graphical tools in optimal policy calculation is also discussed.