Modern Logistics Distribution Center Vehicle Route Optimization Program Research And Application

Logistics distribution is a stage that it is connected with consumer directly. The costs of distribution are very high in all kinds of logistics costs. The rationality of vehicle scheduling will influence on speed, cost, profit of logistics greatly. The delivery vehicles are divided into Vehicle Routing Problem and Vehicle Scheduling Problem according to their space and time characters. Some scholars call VRP with time window VRPTW.This thesis is based on the project of "The Modern Material Handling Distribution System for Jinan Tobacco Company". Taking into account the specific constraints such as streets direction and road conditions, collecting the requirements of the enterprise, classifing and analyzing the algorthms of VRP, this thesis divided the VRP into two steps. First step is route area partition problem. Phsical area partition is an effective method to solve computer calculate speed because there are thousands upon thousands delivery nodes in the tobacco business distribution center. Second step will solve an single vehicle routing problem which we call Traveling Salesman Problem (TSP). Thus we can reach a satisfactory compromise between reasonable computer calculation time and precision to the VRP which is a NP-hard problem. The method has a generality to the VRP that has a depot and a large number of delivery nodes. Based on the operational theory, this thesis is focusing on the application of heuristics VRP algorithm, include C-W saving and improved saving mileage algorithm, 2-Phase (Cluster First Route Second) algorithm, VRP with soft time window. We set up the database of actual streets' distribution nodes and other key nodes based on GIS and calculated the shortest distance between arbitrary two nodes. The grid partition technology is applied to solve metropolis distribution network. The above method is implemented based on the VB, Maplnfo Professional andAccess database platform. We make the programs improving and upgrading on computer efficiency and put the software into action. This thesis will compare the results with former system by graphical methods.At present, most domestic researches on VRP are based on the hypothetical abstract network or on the small scale distribution nodes. Few people study the VRP based on the real traffic road and large scale delivery network nodes. This is the significance of this subject.