A re-examination of the effectiveness of priority rules in a dynamic job shop environment

III dyiiaiuic job .shop .sdiccliiliiig li(cra(urc, an cxicnsivc research clioil lias been spent to study the performance of priority rules, wliich play an important role to manage scheduling tasks in real life manufacturing systems. This study extends the previous research on priority rules by investigating the effect of due date, processing time, and load variation on the pei (drmance of some well used priority rules in a Job shop environment. Furthermore, tliis study will analyze the performance of the rules under the due window approach. The performance of the rules will be measured in terms of two regular criteria: mean flow time and mean tardiness. In addition, with the incieasing emphasis on using non regular measures, we further study the performance of the rules with respect to the mean absolute deviation (MAD) criterion. Finally, we propose two new rules that perform quiet effectively for the MAD criterion.