Orders Loading and Release in Flow Shops including Outsourcing Networks

Purpose of this paper is to analyse and compare the behavior of workload control models in flow shops of both the MTO (Make-To-Order) and MTS (Make-To-Stock) classes. A simulation model has been built, where a manufacturing cell is loaded through an input control mechanism with shop orders coming from a “pool”. The “pool” itself is fed with planned orders coming from an MRP system. The MRP system releases production orders every planned period and the input control mechanism decides for the actual release of work orders. Conclusions are drawn for the performance of the system with or without an MRP system and with or without the input control mechanism in MTO and MTS environments. Compared to the pure flow shop routing, any set of stations might be excluded from the routing or replaced by subcontractors belonging to an outsourcing network of the manufacturing company. Thus, the general flow shop may still show routing variety with respect to routing lengths, though there is one flow direction with outsourcing interruptions.