Study On The Location Of Overseas Warehouses Considering Four-stage Transportation Process

With the continuous improvement of the Internet technology and the development of economic globalization,China's cross-border e-commerce shows a rapid development trend.The rapid development of cross-border e-commerce is inseparable from the support of cross-border logistics.As a major innovation of cross-border logistics mode,overseas warehouse can shorten the distribution time,reduce the cost of logistics distribution,improve the efficiency of return and exchange and customer satisfaction.Therefore,the overseas warehouse location problem has become one of the most important research issues on cross-border logistics and overseas warehouses.This thesis focuses on the whole process of export cross-border e-commerce transportation,and studies the location of overseas warehouses.The main research works of this thesis are as follows:(1)This thesis first describes the research background and significance of overseas warehouses and the related researches.Through the literature review on overseas warehouse location problems and traditional location(facility location and hub location)problems,we find that,by using 1-4 dimension decision variables,the previous location problems are mainly described based on the facility location models.From the perspective of cargo transportation process,the previous overseas warehouse location problems simplify the transportation process from domestic exporters to foreign customers to some extent.Obviously,transportation costs will have a great impact on the location of overseas warehouses.Therefore,our overseas warehouse location problem combines the hub location model and facility location model,and we comprehensively consider 4-stage transportation process:transportation from domestic exporters to domestic ports,from domestic ports to foreign ports,from foreign ports to overseas warehouses,and from overseas warehouses to foreign customers.(2)In order to describe the 4-stage transportation process from domestic exporters to foreign customer and consider two types of overseas warehouses,6-dimensional decision variables are used for formulating the overseas warehouse location problem.By minimizing the total cost,a mixed integer linear programming model is proposed for our problem.The traditional location problems belong to NP-hard problem,and our studied problem is more complex than the traditional location problems.In order to verify the rationality and effectiveness of our proposed model,CPLEX is used for solving a small-scale example taken from the cross-border e-commerce overseas warehouse location problem between China and Europe,and the results are analyzed.(3)Since our problem is NP-hard,it is difficult to get the optimal solution for large-scale problems.In order to solve large-scale problems,this thesis designs a hybrid genetic algorithm based on labeling method.Namely,genetic algorithm is used to determine the location decision of overseas warehouses through coding,selection,crossover and other genetic operators.When the location decision is fixed,the remaining problem can be transformed into the shortest path problem,which can be solved by label method.In large-scale numerical experiments,this thesis focuses on the comparison between direct shipping mode and the overseas warehouse mode.Moreover,the effects of scale economies on overseas warehouse locations are mainly explored.