A comparison of mean reduction versus variance reduction in processing times in flow shops

A constant industry challenge is to find ways to improve production capabilities within the boundaries established by constrained resources. There are several types of production improvement that represent laudable management goals, and there are many ways to achieve production improvement goals. In this paper, we focus on two production metrics and two means of improvement. Specifically, we are concerned with finding ways to decrease manufacturing work in process levels and cycle times in flow shops. A common method of improvement is through mean processing time reduction that is frequently brought about by technological improvements in processing equipment. Another common means of improvement that is receiving increasing attention in the literature is variance reduction. Herein, we quantify and compare the levels of improvement brought about by reduction in both mean and variance of processing times.