随机需求下选址——库存问题

An Inventory-Location Problem with Stochastic Demands

在由多个零售商和多个分销中心组成的供应链网络中,零售商的数量及位置已给定,零售商处的顾客需求是随机的。优化决策是确定分销中心的数量和位置、每个分销中心负责的零售商组、各零售商的订货策略,目标是使系统长期运行下的总成本达到最小。将这种选址——库存问题建模为整数线性规划模型,利用拉格朗日松弛方法和启发式算法分别获得问题的上下界,然后设计求解算法,并通过大量的算例考察算法的有效性。

A supply chain network is formed by a set of retailers and a set of distribution centers, in which the number of retailers is given, and the customer demands are stochastic. The decision is to determine the number of distribution centers and their locations, the partitions of retailers to the determined distribution centers, and the inventory policies of the retailers. Such location-inventory problem is formulated into an integer linear programming model with the objective minimizing the total cost for infinite horizon. By using the Lagrangian relaxation method together with a heuristic procedure, lower bounds and upper bounds are found, through which approximation solutions are obtained. Numerical computation results are provided to illustrate the solution approach.