Buffer allocation in unbalanced three-station serial lines

The paper considers the problem of allocating buffer storage to unbalanced serial production lines so as to maximize steady-state throughput. It focuses on the three-station line whose processing time probability distributions differ in either or both mean and variance. The paper develops rules of thumb for the optimal placement of buffers, and demonstrates the counterintuitive result that a balanced or nearly balanced buffer allocation is optimal for many highly unbalanced lines. It also demonstrates that an imbalance in means has a greater impact on buffer allocation than an imbalance in variances. Finally, the paper explores the extension of these results to the general serial line.