Benders Decomposition for Large-Scale Uncapacitated Hub Location

This paper describes an exact algorithm capable of solving large-scale instances of an important hub location problem called the Uncapacitated Hub Location Problem with Multiple Assignments. The algorithm applies Benders decomposition to a strong path-based formulation of the problem. The standard decomposition algorithm is enhanced through the inclusion of several features such as the use of a multicut reformulation, the generation of strong optimality cuts, the integration of reduction tests, and the execution of a heuristic procedure. Extensive computational experiments were performed to evaluate the efficiency and robustness of the algorithm. Computational results obtained on classical benchmark instances (with up to 200 nodes and 40,000 commodities) and on a new and more difficult set of instances (with up to 500 nodes and 250,000 commodities) confirm the efficiency of the algorithm.