Research On Multi-echelon Network Location-routing Planning For City Joint Distribution Of Online Shopping Logistics

In recent years,the rapid development of China's e-commerce and the expansion of the online retail market have provided a solid foundation for the development of the online shopping logistics industry.Urban distribution is the supporting link of online shopping logistics,and its operation mode,network layout,and vehicle scheduling directly affect social logistics costs,enterprise distribution efficiency and customer service experience level.However,the traditional extensive enterprise independent distribution model has a series of social and enterprise-level problems,such as high social logistics costs,redundant allocation of resources,transportation and environmental problems,cost and price difficulties,and low service levels.At present,with the development of e-commerce,urban distribution has three new characteristics: multiechelon distribution,coexistence of delivery and pickup requirements,and social multiobjective needs.These new characteristics are urgently needed to be taken into account in the operation of urban distribution.Based on this,how to deeply consider the new characteristics of urban distribution and apply the joint distribution model to efficiently carry out urban distribution has become a very valuable and urgent problem to be solved.Therefore,this paper studies the location-routing optimization problem of urban distribution network construction under the joint distribution mode.(1)Analyze the problem.Analyze the characteristics and existing problems of current online shopping logistics city distribution,and analyze the three characteristics of current urban distribution: multi-echelon distribution,multi-object requirements,and coexistence of delivery and pickup requirement.(2)Construct a mathematical model of the problem.The goal is to minimize corporate distribution costs,maximize customer satisfaction,and minimize carbon transaction costs.Study the quantification and measurement methods of the three objectives,and construct a multi-objective function.Based on the perspectives of resource optimization,customer satisfaction and environmental friendliness,three new characteristics of urban distribution are considered,and finally construct a multi-objective two-echelon locationrouting planning model for online shopping logistics city joint-distribution considering simultaneous delivery and pickup.(3)Design model solving algorithm.Design the interrelated two-stage hybrid heuristic algorithm i-IA-NSGA?.In the stage of satellite selection and customer allocation based on immune algorithm,problem-specific design of customer allocation strategy and antigen-antibody affinity is carried out.In the stage of vehicle route planning based on NSGA ?,targeted improvements are made in generating initial feasible solutions,selecting cross mutation,elite retention strategies and solution output strategies.(4)Conduct case application research.Taking the delivery network construction of express company Y and S in Yuzhong District of Chongqing City as the research object,it verifies the effectiveness of the joint delivery model,the model and the algorithm in this paper,and conducts sensitivity analysis on the combination of models and customer satisfaction.This paper studies the joint optimization of distribution network facility location and vehicle routing under the urban joint distribution model,and aims to solve the problem of the refined operation of urban distribution,and provide effective decision-making basis and technical support for the development of real urban distribution.