Research On Vehicle Routing Problems In Logistics Distribution

With the development of the human society, the solution of the question already not merely pauses in the feasible angle, but faces the direction to being succinct, highly effective and fast advanced, not only requests to have to meet people's general need in life and study, but also requests to consume the least resources of time and space, achieves the best result by the minimum price. The modern research of the logics management is an example.Along with the logistics industry develops to the globalization, the information and the integrated, the function of the delivering in the entire logistic system become more and more important. The transporting system is the most important sub- system in the delivering system, the transporting expense occupies about 50% in the whole expense, and therefore if we want to reduce the logistics'cost, we should first to reduce the transportation cost. Among them, whether the transports'line reasonable directly influences the speed, the cost and the benefit, especially the determination of the multi-users'delivering line is a complex engineering system.In highly rhythm and efficiency society, the goods delivering not only must satisfy the request of the normal goods delivering, but also need to consume the least material resources, the human resources, the time resources and so on.In the logistics delivering, the vehicle routing problem affects broadly area, and needs to consider a lot of factors, the influence to the enterprise to improve the grade of service, to reduce the cost of the logistics, to increase economics'efficiency is big. Because the enhancement of the request of delivering service in the market economy, the time factor in the delivering process become more and more important. In view of this, this article will emphatically study the vehicle routing problem with time windows.The delivering problem is the key in the logistics'policy-making. Generally speaking, except outside the product's cost in purchase, the transportation cost occupies higher proportion than any other things. Although there are many kinds of transportation forms, the most important things are transportation's mode choosing,vehicles dispatching and planning and so on.Selecting the appropriate vehicle routing may speed up the response to the customers'demand, improve the grade of service, enhance the degree of customer s'satisfaction, reduce the service business operation's cost. According to such a kind of urgent demand, in the computers'highly developing day, how to let the computer simulate the process of logistics delivering, and finally produces the most succinctly and highly effective delivering plan, has since always been a focal point which the multitudinous computer scholar study, and from this grows a new research topic──Vehicle Routing Problems, VRP. Through the various countries general researcher's joint effort, already have proposed many type of optimal solution and the near superior solution model and its imprecise and the heuristic algorithm to solve the different type of the VRP, as well as corresponding software package. Compared with the international, domestic's VRP research is later, only gradually emerges in the1990s, compared to overseas relatively fall behind for more than 30 years. At present, domestic's complex vehicle routing problem research is only started.Based on the analyzes to the question which exists in the present VRP research in detail, this article first elaborates the logistics delivering problem and the vehicle routing problem in the link of the logistics delivering problem in detail, including researching background, domestic's and international's present researching situation which proposes to this question, as well as the research theory's basis and the existence question will make the profound analysis and the summary. And list a unified mathematical model according to the goal and the restraint, which will need to consider in the VRP. This model may act according to various goals value degree, which the different unit to give each goal auxiliary by the different weight value, or arrange the target according to the priority. According to the study of this question, this article has explained the developing process each algorithm principle and the implementation which domestic and foreign appears in detail, and analyzes each algorithm the good and bad points, explained its most suitable to solves what kind of problem. According to the established mathematical model, this article looks for a typical logic delivering case, uses C-W method to solve this problem. Finally, this article makes the summary and the forecast to this research area.