需求和回收均随机的最优库存控制研究

Research on Optimal Control of Inventory with Stochastic Demand and Return

为了对回收物流进行有效管理,对回收品采用批量修复的方式,构建了基于定期处理的回收物流确定型和随机型库存控制模型,得出了确定模型的最优决策变量;同时将确定模型的最优订货批量和最优再制造期分别作为随机模型的最优订货批量和最优再制造期,对替换产生的误差进行了仿真分析。仿真结果表明,替换后的单位时间成本最小值与实际最小值误差非常小,随机模型最优决策变量的计算复杂度显著降低,有效地拓展了其实用性。此外,还分析了需求标准差、回收速率与需求速率的比率,以及零售商订购提前期与替换误差的关系。

The batch method for returned items was applied for the effective management of returned logistics. A deterministic model and a stochastic model were developed based on periodic review. The optimal decision - making variables were concluded. The optimal order batch and optimal remanufacturing period for stochastic model was used as the determined models respectively. The results of the simulation analysis of the errors show that the errors of replacement are very small, which decreases the difficulties of computing stochastic model and develops its practicability. What＇s more, the relationship between the replacing errors and the standard deviation of demand, fraction of demand returned as well as the order lead time were analyzed.