Abstract:

In this paper, the two-echelon Inventory Routing Problem（IRP） within the mode of Vendor Managed Inventory（VMI） is studied in accordance to the characteristics of demand fluctuation. A mixed-integer programming model on two-echelon IRP with heterogeneous fleet is developed to minimize the total system cost of a two-echelon IRP. An improved particle swarm optimization algorithm is designed to solve the model. Numerical experiments verify the applicability and effectiveness of the model and the algorithm proposed in this paper. The results indicate that using heterogeneous fleet can not only increase the loading rate of distribution vehicles and decrease the inventory levels in retailer warehouses, but also reduce the total system cost of the two-echelon IRP. Sensitivity analysis shows that no matter how the demand fluctuates, the total system cost of a two-echelon IRP will be reduced when using heterogeneous fleet.

Key words: Vendor Managed Inventory（VMI）, two-echelon inventory routing problem, heterogeneous fleet, optimal model, particle swarm optimization

摘要：

针对供货商管理库存（Vendor Managed Inventory，VMI）模式下的二级库存路径问题（Inventory Routing Problem，IRP），结合需求的波动特征，以二级库存路径问题系统总成本最小化为目标，建立异质车队的二级库存路径问题混合整数规划模型，并设计改进的粒子群算法对模型求解。数值实验分析验证了模型和算法的适用性和有效性，结果显示，使用异质车队不仅可以提高配送车辆的装载率，降低零售商的库存水平，还会减少二级库存路径问题系统总成本；敏感性分析表明，不论需求波动程度怎样变化，使用异质车队时二级库存路径问题系统总成本都会得到降低。

关键词: 供货商管理库存（VMI）, 二级库存路径问题, 异质车队, 优化模型, 粒子群算法