A simulated based approach to develop new approaches for ?due date assignment? and ?job release? in multi-stage job shops

Workload control (WLC) concepts are advocated as one of the new productionplanning and control (PPC) methods. In its elaborated form, WLC includes threemajor decision levels: (i) job entry, (ii) job release, (iii) priority dispatching. In eachdecision levels, several decision points which have significant impact on theeffectiveness of the PPC are defined (i.e. acceptance/rejection, due date assingmentetc.). In order to improve the effectiveness of PPC, WLC systems should consider allthese decision points simultaneously. In adddition to these decision points, flexibilityof the shop can be included as the fifth decision point which allows the shop capacityto be adjusted as new orders enters the system and as they are released to the shopfloor.In this study, simulation models which enable the effect of each decision pointswithin this WLC concept to be explored are developed and tested. The resultsrevealed that simultaneous consideration of decision points improves theeffectiveness of PPC. Moreover, a composite dispatching rule which can be used inpriority dispatching level to improve the effectiveness of other levels is developed byusing a data mining tool.Keywords: production planning and control, workload control, simulation, datamining