Resource Levelling

3.9 Conclusions

In this chapter, we have studied the problem of assessing resource usage in scheduling with incompatibilities. Contrary to what appears in the literature, we have proposed a local search algorithm which simultaneously takes into consideration three different objective functions, i.e., the minimization of the resource imbalance, and the minimization of the peak of resource usage and the makespan. Extensive experiments on synthetic data, as well as a comparison with lower bounds and known heuristics have been presented. The latter tests have been performed by adapting our algorithm to incorporate precedence constraints. What has emerged is that the proposed local search is able to find high quality solutions, especially if we consider the difficulty of dealing simultaneously with the three problems considered. Two case studies are presented at the end of the chapter.