A Parallel Algorithm for Minimizing the Fleet Size in the Pickup and Delivery Problem with Time Windows

Abstract

In this paper, we propose a parallel guided ejection search algorithm to minimize the fleet size in the NP-hard pickup and delivery problem with time windows. The parallel processes co-operate periodically to enhance the quality of results and to accelerate the convergence of computations. The experimental study shows that the parallel algorithm retrieves very high-quality results. Finally, we report 13 (22% of all considered benchmark tests) new world's best solutions.