PERIOD BATCH CONTROL IN GROUP TECHNOLOGY

Group technology (GT) offers many advantages to firms engaged in batch manufacturing, including lower setup times, reduced lot sizes, lower lead times, and easier production planning and control. Period Batch C ontrol (PBC) has been proposed in the literature as a simple productio n planning and control system for a GT environment, based on the choic e of a cycle length. Unfortunately, there are no published studies pro viding guidelines for the choice of an optimal cycle length. In this p aper we develop a cost minimization model for examining the choice of cycle length, and demonstrate its use by applying it to four published data sets. The analysis shows that the cell design itself directly af fects total inventory and overtime costs and the choice of cycle lengt h; that demand increases can be very expensive for a given cell design ; and that the degree of demand uncertainty is an important factor in PBC design. The key managerial consideration is the amount of slack ca pacity to build into the cell designs to handle demand uncertainty. Fi nally, we studied the effect of safety stocks on costs and cycle lengt hs. Results indicate that safety stocks can reduce both total cost and cycle length.