Exact and Heuristic Methods for Minimizing the Total Completion Time in Job-shops
Résumé
In this paper we consider the total completion time minimization in a job-shop. We propose a new mathematical formulation based on a strip packing model. This formulation is enhanced by introducing some valid inequalities in order to compute an efficient lower bound. It is also exploited to derive an exact method; branch-and-bound algorithm which uses an improved solution of a genetic algorithm. The proposed algorithms are tested on standard benchmarks and the results are satisfactory in term of solution quality and the distance to the optimal solution.