Research On Vehicle Routing Problem With Pick-up & Delivery And Time Windows

With the continuous development of logistics industry and the constant improvement of the specialization level of logistics in our country, logistics distribution industry has also been developed quickly. Of all the activities in distribution, the vehicle routing problem is the key problem. In addition, it has great much effect on enterprise to upgrade the level of service, reduce the logistics cost and increase economic benefits. To achieve the basic aim of minimum cost and maximum benefits, the trend is to unitize the activities of delivery and pickup together. Therefore, it is of theoretical and practical senses to some extents to study the vehicle routing problem under the environment of unitizing the activities of delivery and pickup for this paper.Based on the former research results, this paper makes a study on vehicle routing problem and finishes the work in the following four aspects:(1) The paper defines the issues of the study and proposes Multi-Depot Vehicle Routing Problem with Pickups & Deliveries and Time Windows problem, and then it establishes the corresponding mathematical model.(2) The simulation optimization method based on heuristic transformation is presented. The heuristic transformation is realized by Matrix Analysis and matrix transformation. By combining the simulation process with the optimization process, it realizes the connection and interaction of simulation and optimization, thus integrating the computer simulation and heuristic optimization.(3) This paper is the first to apply geographic information system (GIS) to vehicle routing simulation modeling. Based on the platform of TransCAD simulation software, it constructed the MDVRPPDTW simulation model. The simulation model provides a visual environment which makes the simulation process more intuitive and the simulation results more easily understood. The simulation model integrates the data in GIS into the simulation platform and uses the data information directly in the simulation process. It constructs a visual simulation environment of the dynamic logistics system to provide better services for decision-making of logistics and distribution.(4) The simulation example shows the feasibility and effectiveness. The paper analyses implications on vehicle routing planning of factors such as time window width, vehicle models and customer points.