Hybridization Based on Problem Instance Reduction

Abstract

This chapter presents an example of a hybrid metaheuristic for optimization based on the following general idea. General MIP solvers such as CPLEX and GUROBI are often very effective up to a certain, problem-specific instance size. When given a problem instance too large to be directly solved by a MIP solver, it might be possible to reduce the problem instance in a clever way such that the resulting reduced problem instance contains high-quality solutions—or even optimal solutions—to the original problem instance and such that the reduced problem instance can be effectively solved by the MIP solver. In this way, it would be possible to take profit from valuable Operations Research expertise that went into the development of the MIP solvers, even in the context of problem instances too large to be solved directly.