Performance of dispatching rules under perfect sequencing flexibility

Presents the results of a simulation-based study of the effects of sequencing flexibility on the performance of various scheduling rules in environments such as job shops and flexible manufacturing systems. A quantitative metric is proposed for sequencing flexibility. Relative differences in the performance of various scheduling rules diminish and the relative rankings also change as sequencing flexibility increases. It is found that the shortest processing time rule may not be the best scheduling rule for reducing inventories and flow times if sequencing flexibility is present in product structures and is used to advantage. Effects on due-date-related criteria are also presented