The Research Of Vehicle Routing Problems With Transshipment Points

In the dissertation, the vehicle routing problems (VRP) with transshipment points are mainly studied. Firstly, the development, the classifications and the studied object of the vehicle routing problems are introduced. Then, various basic algorithms are given in detail. Secondly, mathematical models, optimized algorithms and numerical examples of several vehicle routing problems with transshipment points are studied.Finally, the direction of future research is suggested.Our main novel work is like follows:(1) First of all, based on the several vehicle routing problems with transshipment points, mathematical models which have practical meanings and convenient to operate are built including of single product on multi-periods problem, multi-products on single period problem and multi-products on multi-periods problem. The feature of the models is add the control variables which is choose the path in to the objective functions. And it made the problem simpler. Meanwhile, it is also the research from single problem to a series of problems. That embodied the idea of a coherent research and the continuous application of the methods.(2) Then the new improved algorithm is given in detail. That is dynamic programming algorithm and hybrid algorithm which is made up by two-phase method and the branch-and-bound algorithm. And a practical numerical example is used to compare the results. The experimental examples show that the improved algorithm can be easy operated. The results and the satisfaction of the solutions have been greatly improved.