基于城市共同配送系统的托盘共用调度随机规划模型

A Stochastic Programming Model for Pallet Pooling Based on Urban Collaborative Distribution System

为推动我国城市共同配送的发展,研究了一个多服务站、多周期、多托盘型号的城市共同配送托盘共用调度问题。在该问题中,托盘可在供应链中循环使用,城市共同配送托盘共用系统管理者需在各服务站拥有的托盘数量、库存能力、运输能力、客户需求量等一系列因素尚不确定的情况下做出调度决策。在对城市共同配送托盘共用调度流程进行分析的基础上,采用随机机会约束规划方法构建了基于城市共同配送系统的托盘共用调度随机规划模型,模型的目标函数为总调度成本最小,约束条件包括需求约束、供给约束、运输能力约束、库存能力约束等。基于Lingo软件编写了求解模型的程序,并通过算例验证了模型的有效性。采用数值分析的方法 ,研究了交通拥堵对期望调度总成本的影响,发现最低期望调度总成本与关键线路的交通拥堵情况呈正相关关系。根据研究结果,城市共同配送托盘共用系统管理者为实现调度成本最低应做到如下3点:一是加强信息化建设,实现供应链可视化管理,降低各类因素的不确定性,提高决策水平;二是在规划服务站时就充分考虑周边线路的交通情况,尽可能将服务站避开交通拥堵路段;三是在运营过程中,密切关注交通情况,科学分析交通拥堵规律,在满足客户时间要求的前提下,尽量避开高峰时段运输托盘。

In order to promote the development of urban collaborative distribution systems（UCDS） in China,a multi-station,multi-period,and multi-type pallet allocation problem over an UCDS is studied. As to the problem,pallets could be reused over a supply chain,and managers of a USDS of pallet pooling have to make decisions when some parameters are stochastic,such as supply,stock capacity,transport capacity,demand,and so on. Based on the analysis of pallet pooling allocation process in an UCDS,a stochastic programming model for pallet allocation in an UCDS is developed using the method of stochastic chance constrained programming. The objective of the model is to minimize the total allocation cost,and the constraints include demand,supply,transport capacity,stock capacity,etc. A program to solve the model is developed with Lingo software,and the effectiveness of the model is verified by case study. The influence of traffic congestionon the total expected allocation cost is studied by numerical analysis. It is found that the minimum total expected allocation cost is positively correlated with the traffic congestion of critical traffic paths. According to the research result,the managers of a USDS pallet pooling should pay attention to the 3 points for minimum allocation cost. First, it is essential to improve information management system and to realize visual management of supply chain,which would be useful to reduce uncertainties of relative factors and improve the decision-making level. Second,it is needed to take traffic conditions into consideration when decide the location of service stations,and service stations should be far away from traffic congestion areas. Third,managers should pay very close attention to the traffic situation and scientifically analyze the traffic congestion rule when the pallet pool is operating,and it is needed to try the best to avoid transport pallets at rush hour,as long as the customers＇ demands could be met on time.