The robustness of selected job-shop dispatching rules with respect to load balance and work-flow structure

Most of the published job-shop research has focused primarily on the identification of dispatching rules which perform well under a variety of shop conditions. Most of the research has assumed that the job shop was an open shop in the sense that a virtually unlimited number of job routeings was possible, as compared to a closed shop, which has much more standardized routeings. Also, most research has further assumed that the capacities at all machines are relatively even, and thus no permanent bottleneck exists. In this research, some of the best-known dispatching rules are studied to determine whether the rules are robust with respect to capacity balance and work-flow structure. In order to be useful in all types of job shop, a rule should perform well regardless of the balance of capacity and work-flow structure in the shop. Results indicate that most of the rules studied are not affected by either of the above factors.