The Vehicle Routing Problem With Simultaneous Pick-up And Delivery With Time Windows

VRP is not only a key link in logistics distribution system,but a crucial point affecting logistics costs.Over recent two decades,a large number of algorithms and models have been developed in academia,and many branches have been derived on the basis of VRP.With the improving commercial requirements,standards of accuracy and punctuality for industries become more stringent when sending and delivering,thus,compared to VRPTW,VRPSPDTW is able to be close to commercial reality preferably.This paper summarizes the classic literatures on VRP and its derivative problems,and analyzes VRPSPDTW in the aspect of its principles,models and algorithms within the case of A Company.The specific study work is as follows:Based on actual transportation mode of auto parts and operational data from A Company,this study aims to satisfy the demand solving and optimizing the pick-up and delivery problem with time windows.Under the precondition,a trade-off between maximum service level and minimum transportation costs on this problem is of primary concern to analyze,and the corresponding mathematical model is established before Differential Evolution is designed to cope with such NP-hard problem.Lastly,by means of applying the modified algorithm to A Company's monthly or weekly dispatching problem,numerical experiment shows that the improved DE are able to obtain better transportation scheme within a short time,which,to some extent,simultaneously improves customer service level and reduces transportation cost.