Heuristics for scheduling sequence-dependent set-up jobs in flow line cells

A key operational issue in cellular manufacturing systems is the scheduling of jobs within a family at each cell. Sequence-dependent set-up times during changeovers from one job to another afford scope for the exploitation of similarities at this stage to minimize the time spent on set-ups. This paper proposes heuristics for scheduling jobs within a part family by identifying subfamilies and sequencing them to improve the use of machines within a cell and to reduce the tardiness as well as the number of tardy jobs. The proposed heuristic, when evaluated by comparison with existing benchmark heuristics, yielded encouraging results.