A parallel cooperative hybridization approach to the p-median problem

The <i>p</i>-median problem is difficult to solve and many heuristic methods have been developed. This paper discusses a new hybridization approach in which existing heuristics are used as ʻexperts’ in a problem-solving team where they cooperate by sharing their solutions with each other. This approach is demonstrated using two heuristics called the ʻvertex substitution method’ and ʻsimulated annealing’. Five cooperation strategies are designed and implemented using an application program interface for parallel programming. Computational experiments show that the strategy named ʻparallel consensus’ can significantly improve the quality of solutions found when compared with the original heuristics. The results also show significant speedups of the program in a multicore parallel computing environment. <br> <b>Keywords:</b> <i>p</i>-median problem, cooperative hybrid heuristics, parallel computing, vertex substitution, simulated annealing, OpenMP