Research On Logistics Distribution Network Design And Solution

Logistics network design and optimization is an important problem for decision-making in the logistics system, which usually can be divided into three layer problem for design: strategy layer, tactics layer and operation layer. They not only each have own problems independently, but also have the integrated problem because of the mu tual influence in them. Analytic method is the common way for the similar optimization problems, the paper firstly gave the problem a systems analysis and literature reviewed on the domestic and international researchers. And then studied on the model and solution for some important problems in LNDP, This main results obtained in this dissertation may be summarized as follows:1. Research on an important problem in the two-echelon logistics networks, to tackle the multiple supply depots, multiple kind products, multiple demands and single period collaborated distribution problem, balanced and transformed the multi-objective problem by diversity of products, and design an improved genetic algorithm to solve the complex combination optimization problem;2. Presented a two layer nested genetic algorithm for multi-layer logistics networks design, which was mixed with simulation annealing algorithm in the method for improved the algorithm's performance. And also discuss on the common principles of algorithm mix methodology, then gave an solution example of the problem, which showed the application and availability of the presented method;3. Location-Routing Problem(LRP) is a NP-hard problem in the integrated logistics system, a solution method based on PSO Problem is presented, which adopted two-layer solution mechanism, the upper layer and lower layer both applied PSO but different code of particle to solve LAP and VRP respectively, and the LAP layer should call the VRP layer's solution to evaluate the particle's fitness. The method is a innovative solution for LRP, and Simulation results of designing LRP examples demonstrated its' effectiveness.4. An mathematical model for LRP based on network theory is put forward, and then for tackling a kind of special LRP, an improved discrete Particle Swarm Optimization algorithm is presented Which adopted the principle of whole optimization, integrated the LAP and VRP, introduced a appropriate coding for the particle, improved the particle's move equation, also added the mutation operator and disturbing operator against the population identical tendency, the applicability and performance of the algorithm has improved. At the last part of the paper, discuss a practical research project about the Zhejang telecom company logistics distribution networks planning, gave the reality problem of LNDP a systems analysis and successful settled.