Li Shuangyan, Li Xialian, Zhang Dezhi, Zhou Lingyun
School of Transportation and Logistics, Central South University of Forestry and Technology, Changsha, Hunan, China.
School of Traffic & Transportation Engineering, Central South University, Changsha, Hunan, China.
PLoS One. 2017 Jan 19;12(1):e0168526. doi: 10.1371/journal.pone.0168526. eCollection 2017.
This study develops an optimization model to integrate facility location and inventory control for a three-level distribution network consisting of a supplier, multiple distribution centers (DCs), and multiple retailers. The integrated model addressed in this study simultaneously determines three types of decisions: (1) facility location (optimal number, location, and size of DCs); (2) allocation (assignment of suppliers to located DCs and retailers to located DCs, and corresponding optimal transport mode choices); and (3) inventory control decisions on order quantities, reorder points, and amount of safety stock at each retailer and opened DC. A mixed-integer programming model is presented, which considers the carbon emission taxes, multiple transport modes, stochastic demand, and replenishment lead time. The goal is to minimize the total cost, which covers the fixed costs of logistics facilities, inventory, transportation, and CO2 emission tax charges. The aforementioned optimal model was solved using commercial software LINGO 11. A numerical example is provided to illustrate the applications of the proposed model. The findings show that carbon emission taxes can significantly affect the supply chain structure, inventory level, and carbon emission reduction levels. The delay rate directly affects the replenishment decision of a retailer.
本研究开发了一种优化模型，用于对由一个供应商、多个配送中心（DC）和多个零售商组成的三级分销网络的设施选址和库存控制进行整合。本研究所探讨的整合模型同时确定三种决策类型：（1）设施选址（DC的最优数量、位置和规模）；（2）分配（将供应商分配到已选址的DC，将零售商分配到已选址的DC，以及相应的最优运输方式选择）；以及（3）每个零售商和已开业DC的订单数量、再订购点和安全库存数量的库存控制决策。提出了一个混合整数规划模型，该模型考虑了碳排放税、多种运输方式、随机需求和补货提前期。目标是使总成本最小化，总成本涵盖物流设施、库存、运输和二氧化碳排放税费用的固定成本。使用商业软件LINGO 11求解上述最优模型。提供了一个数值示例来说明所提出模型的应用。研究结果表明，碳排放税会显著影响供应链结构、库存水平和碳排放减少水平。延迟率直接影响零售商的补货决策。
