Reactive tabu adaptive memory programming search for the vehicle routing problem with backhauls

Abstract

A heuristic approach based on a hybrid operation of reactive tabu search (RTS) and adaptive memory programming (AMP) is proposed to solve the vehicle routing problem with backhauls (VRPB). The RTS is used with an escape mechanism which manipulates different neighbourhood schemes in a sophisticated way in order to get a continuously balanced intensification and diversification during the search process. The adaptive memory strategy takes the search back to the unexplored regions of the search space by maintaining a set of elite solutions and using them strategically with the RTS. The AMP feature brings an extra robustness to the search process that resulted in early convergence when tested on most of the VRPB instances. We compare our algorithm against the best methods in the literature and report new best solutions for several benchmark problems.

Keywords:

• vehicle routing with backhauls
• neighbourhood search
• tabu search
• adaptive memory programming

Acknowledgements

We thank the anonymous referees for their valuable comments and suggestions. I am also grateful to two of my colleagues Professor Salhi and Dr Nagy for reading the drafts and helping to improve the presentation of the paper.