On the merits and pitfalls of critical chain scheduling

The direct application of the Theory of Constraints (TOC) to project manage ment, known as Critical Chain Scheduling and Buffer Management (CC/BM), has recently emerged as one of the most popular approaches to project manageme nt. It is the objective of this paper to highlight the merits and pitfalls of the CC/BM scheduling approach. Following a short overview of the fundame ntals of CC/BM, the strengths and weaknesses of the approach are put into p erspective, based on a critical analysis of the literature as well as our o wn experimentation with commercial CC/BM software. The CC/BM scheduling mec hanism is tested in a full factorial experiment performed on a set of bench mark problems. It appears that the 50% rule for buffer sizing may lead to a serious overestimation of the required buffer protection. Regularly updati ng the baseline schedule and the critical chain provides the best intermedi ate estimates of the final project duration and yields the smallest final p roject duration. Using clever project scheduling and rescheduling mechanism s such as branch-and-bound, has a beneficiary effect on the final makespan. (C) 2001 Elsevier Science B.V All rights reserved.