Refinements to order release and dispatching decisions in Workload Control
Tuesday 25 January 2011, 12:30
LT12, Management School
University of Groningen
Abstract: A large range of companies within the make-to-order sector are classified as job shops. Workload Control (WLC) has traditionally been suggested as a production planning & control concept that fits the needs of this class of companies. WLC emphasises the importance of creating restricted and balanced loads on the shop floor. After the decision of releasing an order to the shop floor has been taken, dispatching decisions are supposed to have a limited impact in shops with low workload levels. Even worse, many dispatching rules have been found to disturb the functioning of the release decision. However, dispatching decisions may gain importance in job shops with long routings, i.e. routings encompassing a large number of production steps.
A recent empirical study in a job shop with long routings showed that dispatching decisions in the final stages of the order routing can have a high impact on final delivery performance. This triggered our research to improve some key decisions of WLC to allow a better functioning of this planning and control concept in shops with long routings. In a recent simulation study we evaluated some possible refinements of WLC release methods to cope with long routings. In another study dispatching rules have been adapted in order to increase synergy with the release decision. The results prove that some very straightforward adaptations may lead to large performance improvements, even in shops with relatively short routing lengths.