Optimization Of Vehicle Routing Problem With Time Windows

With the development of science and technology, the economic modernization is accelerating .All of the countries face both opportunity and challenge. Modern logistics , an advanced technology for companies, which plays a significant role in the development of economy and society ,is regarded as an important way of lowering cost and enhancing productivity. Because of the maturity of Just-in-time theory, advanced industries make a high demand on the time and number of goods' distribution.It is an indispensable product system and logistics system to satisfy the diversified demand .The diversified demand also makes a high demand on the time of goods' transportation. Because the delay of distribution will decrease goods' value, time window becomes more and more important in goods distribution. Obviously, lowering distribution cost, transporting goods timely, improving the service quality, optimizing vehicle routing problem with time windows is exigent to enterprises.Based on such background, this paper will do some research on VRPTW which can help the enterprises to improve their condition.It states the definition of logistics and its infection on goods' value, companies' competetivity, macro economy. It also states the definition and evaluation criterion of distribution. By explaining the significance of goods distribution in logistics, it states the meaning and need to solve VRPTW. The paper collects both foreign and domestic VRPTW literatures, and introduces the status quo of research .It classifies the main method of resolving VRPTW while introducing them and analyzes the merits and demerits of Genetic Algorithm as well as its detailed process. From three angles——distribution cost, degree of customs' satisfaction, vehicle's number, the paper analyzes the unperfectness of existing models, builds an improved multi-objective model to optimizing VRPTW and applies Genetic Algorithm which has strong holistic searching ability and parallel running ability to the model. According to the characteristics of coding, the paper devises special arithmetic operators to get the resolution. This paper analyzes VRPTW mathematically and realizes it by C# . The algorithm given in this paper can obtain an optimized solution effectively and has been proven to be a good one. So, it has a high value to logistic enterprises.