THE EFFECT OF COMBINING SIMPLE PRIORITY HEURISTICS IN FLOW-DOMINANT SHOPS

Previous scheduling research indicates that no single priority heurist ic is effective on all the relevant performance criteria. However, few heuristics have shown to be effective on particular performance crite ria. This study examines this issue further by applying various schedu ling heuristics at different states of three flow-dominant shops (i.e. entrance, intermediate, and exit workstations), under a variety of ex perimental conditions. The experimental factors used are shop load, du e date tightness, and shop structure. Twenty-eight different combinati ons of heuristics were investigated. The results indicate that the app lication of particular priority heuristics at various stages of the pr oduction process has a positive impact on the shop performance. By sel ectively utilizing different scheduling heuristics, it is possible to gain the advantages of each heuristic and at the same time minimize th eir associated shortcomings. Furthermore, the relative rankings of the heuristic combinations are fairly robust to the shop structure factor on all performance measures. Finally, it is shown that the selective use of the shortest processing time heuristic significantly impacts th e performance measures across all experimental conditions.