An Improved Variable Neighborhood Search Algorithm for Multi Depot Heterogeneous Vehicle Routing Problem based on Hybrid Operators

This paper presents an Imporved Variable Neighborhood Search (IVNS) algorithm to solve Multi Depot Heterogeneous Vehicle Routing Problem with Time Windows (MDHVRPTW). The initial solution is obtained by customer allocation and path planning based on a cost network. The hybrid operators of insert and exchange are used to achieve the shaking process and the later optimization process is presented based on hybird operators to improve the solution space, the best-improvement strategy is adopted, which make the algorithm can achieve a better balance in the solution quality and running time. The idea of simulated annealing is introduced to take control of the acceptance of new solutions. Computational results are presented in benchmark instances, which show that our approach is competitive and even outperforms existing solution procedures proposed in the literature. And finally the proposed model and algorithm is applied to the large water project in China to solve the allocation of vehicles and routes.