Models for cellular manufacturing systems design: matching processing requirements and operator capabilities

Cellular manufacturing systems comprise categorizing machines used in the firm's production system into cells dedicated to part families that have similar requirements in terms of tooling, setups and operations sequences. Although worker assignment to cells has a significant impact on cell effectiveness, scant attention has been paid to this issue in previous research. We present two models–sequential and concurrent–for cell formation. The sequential model uses a machine–part incidence matrix (MPIM)-based similarity coefficient while the concurrent model uses a similarity coefficient based on both MPIM and machine–operator incidence matrix (MOIM). Our results show that for 50 problem sets widely reported in literature, the concurrent model outperformed the sequential model in most cases. A measure quantifying the difference in MPIM and MOIM was developed and the relative out-performance of the concurrent model was shown to depend on the value of this measure.