Local improvements that degrade system performance: case studies and discussion for throughput analysis

Much of our intuition about production system performance dynamics is grounded in an understanding of simple serial lines. For this reason, practitioners tend to rely on concepts and principles that have successfully guided the design and improvement of these lines, even in the analysis of significantly more complex systems. Based on this intuition, there is a natural tendency to believe that improving any specific feature of a system will result in comparable or improved overall performance. Unfortunately, this is not always the case. In this paper, we present three case study examples which demonstrate that local improvements to station speed or buffer capacity can result in an overall degradation of system performance for non-serial production systems.