Time- and cost-based priorities for job shop scheduling

Competitively, cost- and time-based scheduling should provide a firm with a powerful market advantage. The cost- and time-based priority scheduling concept is driven by profit maximization and quick response in a competitive market. The literature on shop scheduling contains numerous studies reporting on the use of dispatching rules that are based only on the time criterion. Alternatively there have been only a few published articles that specifically consider a composite of cost and time. Aggarwal and McCarl, and Scudder and Hoffmann have investigated the use of cost and time information for determining the job priority in random job shops. One result of this study is a reconciliation of the differences between the Aggarwal and McCarl and the Scudder and Hoffmann study. Moreover, a simplistic priority rule based on profit margin and due dates is introduced and tested. The results reported in this research are an attempt to reconcile the issue of time-based versus cost-based priority rule performance.