Simulation Model And Optimization Methods For Vehicle Routing Problem

Vehicle Routing Problems (abbr. VRP) is one of the key issues in the field of logistic management. One of the aims of logistic operation and management is delivering right goods to right customers timely with the least cost by means of rationally dispatching vehicles and arranging time and routes. This problem is a difficulty in academic and industrial communities for a long time. A new approach to solving VRPs by simulation methods is presented in the paper. The simulation model for solving VRP is established using logistic system simulation platform—eM-Plant. In order to overcome the two shortcomings that the efficiency of solving a simulation model is low and the simulation module and the optimization module are separated in the process of a simulation, the author improves the simulation optimization method by integrating the simulation process with the optimization process, and presents a new approach to simulation optimization based on heuristic transformation. Finally, the simulation and optimization system of VRP is realized, and computational experiments prove that the above-mentioned methods are effective. The detailed contents studied in the paper are as follows:(1) A simulation model of VRP is constructed. The complexity of VRPs is analyzed and the model of VRP with stochastic constraints is established. However, the model is difficult to solve. In order to solve it, the author presents a global structure of a simulation model, and then designs and realizes the simulation model.(2) The simulation optimization method for VRP based on heuristic transformation is presented. The framework of the simulation and optimization for VRP in logistics distribution system is constructed. By integrating the simulation process and the optimization process, the author proposes the principle and the method of simulation optimization with heuristic transformation. The parameters produced by the simulation process are analyzed using heuristic rules. The matrix transformation is used to optimize search strategies, and then the optimal solutions or satisfying solutions of VRP are found out.(3) The simulation optimization system for VRP is realized and computational experiments are implemented. The simulation optimization software system is designed and realized. The results of computational experiment show that the simulation model based on eM-Plant is effective and that the method of simulation optimization with heuristic transformation is efficient. The method of simulation optimization with heuristic transformation can produce solutions with sound stability and high efficiency. The research in this paper has promoted the interaction and inosculation among Simulation Technology, Optimization and Combinatorial Optimization. It is beneficial to the exploration for solving vehicle routing problem which is NP-hard. The research results can provide decision supports for logistic distribution decision-makers. It is useful for logistic companies to decrease their logistic costs in practice. And the research makes achievements in solving the multi-objective optimization problems in logistic distribution in e-commerce.