Distribution And Set The Vehicle Routing Problem Under The Cargo Integration Study

With the continuous development of logistics industry and the constantly 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, to reduce the logistics cost and to increase economic benefits. To achieve the basic aim of minimum cost and maximum benefits, unitizing the activities of delivery and pickup will be the trend. So, 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.The objects of this paper are the multi-depot vehicle routing problem with pickups and deliveries and the pickups and deliveries vehicle routing problem with hard-windows. Firstly, this paper sets up the mathematic model of the multi-depot vehicle routing problem with pickups and deliveries then solve it by using multi-phases composite heuristics algorithm. The result shows that the total distance traveling by vehicles when integrating pickups and deliveries is about the half of it when separate the two.This paper sets up the mathematic model of the pickups and deliveries vehicle routing problem with hard-windows, design a hybrid genetic/tabu search algorithm to solving this problem. Combine the two methods of structuring by improved C-W algorithm and producing randomly to produce starting group for genetic algorithm and using tabu search for a proportion of better chromosomes. The computing result is 2.1% better Compare with the related literature, which show the suitability of designed algorithm and that structuring a proportion chromosomes for the starting group and using tabu search in the genetic algorithm can help to get better solution fast. At last, the designed algorithm proved to be practicable, scientific and effective by using it to test three suits of standard testing dates which contain the small time-windows, big time-windows and normal time-windows.