New Approach based on Simplification and partially fixing of Problem to solve Large Scale Vehicle Routing Problem

This paper presents a specialized evolutionary approach for large scale vehicle routing problems (VRPs). Our approach includes two original mechanisms; simplification of problem and partially fixing of customers’ sequence. The first one tries to simplify the problem by integrating some neighbor customers into one group recursively and to iterate to restore the simplified problem to original one gradually. And second mechanism is to reduce the search space of the problem by fixing a part of customers’ sequence. Our approach is designed for an effective search in large scale VRPs by the interaction of these mechanisms. Through applying the proposed approach to some test problems having different characteristics, the effectiveness of our approach is determined in comparison with normal approach (without our these original mechanisms).