Product mix selection and closed manufacturing cell flow time performance

Abstract

This research addresses performance issues for Just-In-Time types of “manufacturing cells”. Prior research ignores the pragmatic reality that the formation of manufacturing cells does not always totally eliminate stochastic job arrivals and setup requirements between successive jobs. These issues are addressed in this research through an analysis of the queueing consequences of product mix decisions. Specifically, this research is focused on the linkage between competitive advantage, traditional cell performance measures, and product mix selections. A “closed” shop is considered (i.e., a manufacturing cell that produces to stock rather than to order). Managerial insights are derived for product mix selection. Performance of a manufacturing cell in terms of mean and variance of job flow time is shown to improve with increasing product homogeneity (i.e., reduced variability among setup time requirements and unit processing time requirements). Optimal product batch sizes are also shown to decrease with increasing product homogeneity. Finally, the relationships between product mix characteristics and cell performance measures are related to the shop's competitive advantage.