COMPARISON OF SYSTEMS BASED ON EVOLUTIONARY SEARCH AND SIMULATED ANNEALING TO SOLVE THE VRPTW PROBLEM
This paper presents the design and analysis of several systems to solve Vehicle Routing Problems with Time Windows (VRPTW) limiting the search to a small number of solutions explored. All of them combine a metaheuristic technique with a route building heuristic. Simulated Annealing, different evolutionary approaches and hybrid methods have been tried. Preliminary results for each of the strategies are presented in the paper, where the combination created by some iterations of the best evolutionary approach and some iterations of SA stands out. A more exhaustive analysis of the three methods behaving better is also presented confirming the previous results. The different strategies have been implemented and tested on a series of the well-known Solomon's benchmark problems of size up to 100 customers. One of the described systems combined with a local optimization part that tries to optimize parts of a solution is being used as part of a real oil distribution system, obtaining very satisfactory results for the company.