A workload control procedure for an FMC integrated in a job shop

Abstract

The current paper describes an order release and loading technique, which considers the routing as well as the machine flexibility of a modern job shop production. The workload control approach involves three steps. In the first step ‘lead orders’, i.e. urgent production orders that are either processed on a known bottleneck or are of high value, are identified. Afterwards transfer batches of the lead part types are calculated using the aspired machine time as a control parameter. This parameter defines an adequate processing time of a machining centre before it is set up for a new job. Finally, the bottom-line workload of the machining centres is determined by allocating and sequencing transfer batches. The procedure is tested by a simulation program that replicates the performance of the production facility of a machine manufacturer, consisting of a flexible manufacturing cell that is embedded into a job shop production for heavy parts.

Keywords:

• Scheduling
• Lot sizing
• Flexible manufacturing
• Simulated annealing