Sequencing and scheduling in flowshops with task redistribution

In some manufacturing situations, station tasks or operations can be shifted or redistributed to adjacent stations when adjacent stations have the appropriate equipment and the workers on that station can perform the shifted work to a reasonable level of competency. This paper addresses such an environment and provides a general framework for applying the shifting or re-distribution of tasks methodology to the intermediate storage, no-intermediate storage and no-wait flowshop problems. The outcome of this research is a way in which to utilise more efficiently the general-purpose facilities of this type of production environment and includes mathematical models, recurrence equations and solution techniques for sequencing and scheduling. From an extensive numerical investigation, the benefits achieved by the application of this methodology are detailed.