Research On The Optimization Design Of Express Parcel Land Transportation Service Network

China's express package business mainly covers the domestic light and small pieces delivery market aiming to provide customers with personalized transportation services.Due to the special needs of customers for the timeliness of express package transportation,there will inevitably be a "reverse benefit" phenomenon,that is,the transportation time and transportation cost of express package exist at the same time as a pair of contradictions: if the express transportation enterprises pursue the timeliness of transportation unilaterally,it will lead to the increase of transportation cost;if they simply pursue the minimization of transportation cost,it will lead to the transportation time poor effectiveness.A good express parcel land transportation service network should balance the relationship between transportation time and transportation cost.Therefore,it is of great significance for the development of express transportation enterprises to optimize the express parcel service network and reduce the total transportation cost of the express parcel land transportation service network within the time limit acceptable to customers.The specific research contents are as follows:(1)On the basis of summarizing the research results of domestic and foreign express parcel land transportation service network,the components of express parcel land transportation service network and the characteristics of different modes and structures are summarized,the research objectives,contents,principles and influencing factors are put forward.The current situation and shortcomings of express parcel land transportation service network in China are analyzed.(2)The transportation organization mode of express parcels in pure hub and spoke network and hybrid hub and spoke network are analyzed,considering the main constraints such as flow conservation,hub node capacity,hub node number,service relationship between nodes and transportation efficiency.Then,taking the total cost of service network transportation as the optimization goal,the optimization model of express parcel land transportation service network based on pure hub and spoke network is constructed.On the basis of the pure hub and spoke network,the direct route is introduced,the standard of direct route and the restriction condition of the number of crenels are added,and the optimization model of express parcel land transportation service network based on the mixed hub and spoke network are constructed with the minimum total cost of service network transportation as the optimization goal.(3)The characteristics of the optimization model of express parcel land transportation service network are analyzed.The solution ideas of the optimization model are determined.Then the advantages and disadvantages of the common heuristic algorithm and its application scope are summarized and the optimization algorithm of express parcel land transportation service network based on the micro evolution algorithm are designed.Through the simulation of examples are compared,the model and algorithm are proven to be able to reduce the total transportation cost,improve the transportation efficiency,and effectively solve the optimization problem of express parcel land transportation service network.(4)Based on the case study of 41 city nodes in East China of China Post,the location and layout of hub nodes and transportation route planning scheme in East China are solved,and the land transportation service network in East China is optimized.The sensitivity analysis is carried out by changing the three model parameters of hub node number,direct route operation standard and transit times,which verifies the correctness and practicability of the optimization method of express parcel land transportation service network.