Optimizing Research of an Improved Simulated Annealing Algorithm to Soft Time Windows Vehicle Routing Problem with Pick-up and Delivery

In this article, we present a more practical mathematical model of vehicle routing problem with pick-up and delivery, which considers the soft time request, vehicle fixed cost, vehicle full-load coefficient. The simulated annealing algorithm was improved to solve the model, the exchange in the lines and between the lines were both used to produces the new solution, through increasing the memory function, using the double termination criterion. We test the new algorithm through a certain scale example, the experimental results show that the new algorithm can obtain better solution, better stability, and high calculation efficiency.