Strategic oscillation for the capacitated hub location problem with modular links

The capacitated single assignment hub location problem with modular link capacities is a variant of the classical hub location problem in which the cost of using edges is not linear but stepwise, and the hubs are restricted in terms of transit capacity rather than in the incoming traffic. This problem was introduced by Yaman and Carello in [18] and treated by a branch-and-cut and a tabu search metaheuristic. We propose a metaheuristic algorithm based on Strategic Oscillation, which was originally introduced in the context of tabu search. Our method incorporates several designs for constructive and destructive algorithms, together with associated local search procedures, to balance diversification and intensification for an efficient search. Computational results on 118 instances show that, in contrast to exact methods that can only solve small instances optimally, our metaheuristic is able to find high-quality solutions on larger instances in short computing times. In addition, our new method which joins tabu search strategies with strategic oscillation outperforms the previous tabu search implementation.