Autonomous distributed approaches for pickup and delivery problems with time windows

We consider the pickup and delivery problem with time windows as one of the practical transportation problems. The problem requires that any paired pickup and delivery locations have to be served by one vehicle and the pickup location has to be scheduled before the corresponding delivery location in the route. In this paper, to search a set of routes close to the optimal one, we propose autonomous distributed approaches based on the search space decomposition for the problem. In this approach, first, the search space is divided into sub-spaces based on the number of customers loaded on each vehicle. Then, the genetic algorithm is applied to these sub-spaces. The effectiveness of the proposed approach is evaluated by computational experiments.