A sequencing heuristic for dependent setups in a batch process industry

Microcomputer-based scheduling systems are dramatically enhancing the ability of manufacturing firms to respond rapidly to changing customer demands and to improve production efficiency. Pendegraft [11], Sullivan and Secrest [14], and Hodsen, Muhlemann and Price [7] provide examples of optimizing schemes that are microcomputer-based. These systems, though do not address sequencing problems with dependent setups nor do they provide efficient rescheduling capabilities required by many practical scheduling environments. This paper presents the development and application of a heuristic approach for scheduling jobs on parallel processors given sequence dependent changeover costs. The model provides for simultaneous processing of single or multiple products, the latter of particular concern in the batch process industries where machine utilization is of immediate concern. An industrial application of the sequencing heuristic at a fiberglass company indicates that cost savings arising from reduced setups can be accrued from the use of the model. The sequencing heuristic is easily understood in terms of its solution methodology and thus more likely to appeal to actual production schedulers.