This paper presents twelve methods for makespan minimization for flexible flow line scheduling problems. This environment is characterized by the ability of jobs to skip stages. Sequence-independent setup times, which can be either anticipatory or non-anticipatory, are also considered. The statistics used to evaluate the heuristic performances were the rate of success (in finding the best solution), the relative deviation, the standard deviation of the relative deviation and the average computation time. A lower bound for makespan was developed to evaluate the solution quality of the proposed methods. The computational tests proved the effectiveness of the heuristic based on the initial sequence using the descending order of the sum of the processing and setup times of all stages and the sequencing of subsequent stages by the order of the job release times.
Production scheduling; Flexible flow line; Sequence-independent setup times
