Off setting lower routeing flexibility incellular manufacturing due to machine dedication

Abstract

We use queueing network models to show that with other factors held constant, the transformation of a functional into a cellular layout causes average work-inprocess levels to increase because of a loss in routeing flexibility resulting from the dedication of machines to part families. However, in practice cellular layouts provide important benefits to counteract this loss in routeing flexibility. We use deterministic models to investigate the potential benefits of four characteristics of cellular layouts: (1) operations overlapping, (2) setup time reduction, (3) reductions in move times, and (4) the simultaneous setup of all equipment in a cell. Stochastic operating environments are investigated with simulation models, which provide evidence that these four characteristics will o ffset the reduced routeing flexibility in practice. In addition, the models show that as the congestion level increases, the need also increases to o ffset this loss in routeing flexibility.