TITLE:
Conditional Lot Splitting to Avoid Setups While Reducing Flow Time
AUTHORS:
Jacob V. Simons Jr, Mark E. Kraus, Willis Mwangola, Gerard Burke
KEYWORDS:
Lot Splitting; Scheduling; Setups; Shop Floor Control; Simulation
JOURNAL NAME:
American Journal of Operations Research,
Vol.2 No.4,
November
30,
2012
ABSTRACT: Previous research has clearly and consistently shown that flow time advantages accrue from splitting production lots into smaller transfer batches or sub-lots. Less extensively discussed, and certainly undesired, is the fact that lot splitting may dramatically increase the number of setups required, making it impractical in some settings. This paper describes and demonstrates a primary cause of these “extra” setups. It then proposes and evaluates decision rules which selectively invoke lot splitting in an attempt to avoid extra setups. For the closed job shop environment tested, our results indicate that conditional logic can achieve a substantial portion of lot splitting’s flow time improvement while avoiding the vast majority of the additional setups which would be caused by previously tested lot splitting schemes.