Two Look-Ahead Strategies for Local-Search Metaheuristics

The main principle of a look-ahead strategy is to inspect a few steps ahead before taking a decision on the direction to choose. We propose two original look-ahead strategies that differ in the object of inspection. The first method introduces a look-ahead mechanism at a superior level for selecting local-search operators. The second method uses a look-ahead strategy on a lower level in order to detect promising solutions for further improvement. The proposed approaches are implemented using a hyper-heuristic framework and tested against alternative methods. Furthermore, a more detailed investigation of the second method is added and gives insight on the influence of parameter values. The experiments reveal that the introduction of a simple look-ahead strategy into an iterated local-search procedure significantly improves the results over tested problem instances.