A despatching rule to allow trade-offs between inventory and customer satisfaction

In job-shop scheduling research, the shortest processing time despatching rule (SPT) has received considerable attention. Several truncated shortest processing time (SPT) despatching rules have been published in the literature. The motivation for such rules is that SPT despatching will frequently result in favourable inventory levels but unfavourable due date performance. Thus, the truncated SPT rules periodically switch from SPT despatching to despatching by some other rule. Owing to the complexity associated with these truncated rules, their implementation is doubtful. As a result, a modified truncated rule is presented that is easy to implement and yet performs favourably with respect to inventory and due date performance.