Postal Vehicle Scheduling Problem

The postal vehicle scheduling problem was firstly proposed by Dantzig and Ramser in 1959. For the theory of this problem is involved in many disciplines and many practical problems can be induced into it, vehicle scheduling problem has always been the hot one in operations research and combinatorial optimization domains. The Kunming Postal central bureau is shouldering the Yunnan province postal commodity transportation and the vehicle dispatch. During the crucial time modern logistics enterprise reforming, construct the modern synthesis VRP system have the important theory and the practice significance to research on the theory of VRP and algorithm research.From the angle of facing application, this paper is about the Postal VRP, which is followed by "puts up problem, analyses the problem, constructs model and algorithm" .In term of the restrains and objective, the general mathematics model is introduced, use the genetic algorithm to solve the problem. The paper provides integrative design thought for the vehicle scheduling system and explains the functions of complete framework, work process, system structure and each module. This paper puts forward an improved genetic algorithm on the base of analysing the research on VRP in China and abroad. The improved genetic algorithm uses integer coding, penalty function to solve constraints, improves crossover operators and mutation operators and uses some operations to deal with illegal individuals until they are legal.The algorithm given in this paper can obtain an optimized solution effectively and has been proved to be a good scheme to solve VRP. So, it has a high value to the postal logistic enterprises to decrease the cost, to improve the level of logistics management, to response customers more quickly and to improve the rival ship power of the postal enterprise. In the last, the chapter is a conclusion, including summary andforecast which summarizes and looks ahead and brings forward what is going to do at next step. It point out some considerations concerning genetic algorithms to be further studied and developed.The postal VRP is a typical strong NP- hard problem .Because it can enrich research areas of logistics science, operation research and combinatory optimization, meanwhile, provides the method and the way for the postal vehicle scheduling system in order to realize the computation management.