| Summary |
In recent years, the variety and volume of the products for consumers have been increasing. In such an environment, competition among enterprises is becoming fiercer. In order to meet consumer’s needs and improve service levels, manufacturing and logistics can be an integral part of the operation of a company. In addition, the forward and reverse logistics must be dealt with in a coordinated fashion. Therefore, industry and academia have paid a lot more attention to the Vehicle Routing Problem (VRP) related research. Among them, the Vehicle Routing Problem with Simultaneous Pickups and Deliveries (VRPSPD) is an important variant of VRP. In particular, it is not only more in line with real world operation.
In recent years, more and more people have begun to pay attention to the environmental issues and the reverse logistics. If the entire logistics process is not properly planned, it will cause a lot of unnecessary waste, excessive raw material and energy consumption, which are harmful to the environment. Therefore, many prior studies have incorporated the production side issues into the distribution process, aiming to effectively reduce waste and reduce total operating costs.
This study focuses on the issue of simultaneous pickup and delivery while considering production requirements. Based on the requirement on the production end, then the numbers of different types of products to be picked up are determined, instead of picking up all the products from the customers. Compared with most VRPSPD studies, in which both pickup and delivery demands of the customers must be met, our study belongs to the problem type with selective pickup. For the concerned decision problem, this study develops an algorithm based on the structure of Tabu Search to solve it, and integrates the algorithm with linear programming model to deal with the issue of selective pickup. The computational results show that a good quality and feasible solution will be obtained in a reasonable computing time. In addition, if decision makers can relax the limitation of VRPSPD, picking up less products back to depots, then, to some extent, part of routing cost will be saved |
