Local Search Heuristic for Multiple Objective Coil Scheduling Problem on Unrelated Parallel Machines

This paper researches coil scheduling problem on unrelated parallel continuous annealing production lines, in which two objectives are considered, one is to minimize total tardiness, the other is to minimize the total completion time. To solve this problem, local search method based on ideal point methods is proposed. Firstly, the two objectives are taken into account, respectively. With consideration of the first objective, a linear programming formulation is set up, and then the ideal point can be obtained by standard LP solver. The other objective is dealt by heuristic. At last, a local search heuristic is proposed to find solutions closing to ideal points. Computational results indicate that the proposed algorithm can find satisfactory solutions in reasonable time.