Express Distribution Center Location And Distribution Routing Optimization Under Joint Distribution

Express logistics industry is facing greater challenges from the development of Internet and E-commerce,such as high logistics costs,low level of logistics services,transport environmental and safety problems.To realize the harmonious and healthy development of express logistics industry,exploring an effective coordination mode of courier delivery and optimizing the configuration of resource distribution system are two important issues.This paper can be described into the following three parts:first,by investigating and analyzing studies of distribution model and the current domestic express,the city express joint distribution model was proposed and its main operational processes was explained;second,the city express multi-distribution center location problem was solved by the k-means clustering algorithm with center-of-gravity method in lmatlab software;third,by researching vehicle routing problem(VRP)of city express joint Distribution,Geographic Information System(GIS)was introduced into vehicle routing problem with soft time windows(VRPTW),and an optimization mathematical model based on road network was proposed.In order to solve this problem,the genetic algorithm(IGA)was improved by combining elitist remaining and roulette strategy.Finally,this solution was tested by a real example.The results indicates that compared to the basic genetic algorithm,the total cost of improved genetic algorithm in solving VRPTW was reduced by 17%.In a joint distribution express projects of Haidian district universities,IGA based on GIS is used to solve the VRPTW problem.The results show that as the business increase of each delivery enterprises,compared to all enterprises distribute separately,the total cost under the joint distribution mode was reduced by 24%,13%and 7%;the number of vehicles was reduced by 23%,12%and 6%.Without considering fixed costs of distribution centers,the city express joint distribution model shows more pronounced effect in small quantities and multi-user load distribution conditions.And as the integration of supply chain process,the implement of JIT and lean logistics,city express joint distribution model will show greater superiority.