Buffer Sizing Methods to Compare Critical Chain Project Management with Critical Path

Critical Chain Project Management (CCPM) provided a tangible progress to the Project Management Body of Knowledge. The critical chain project management (CCPM) differs from the traditional Critical Path Method (CPM) which includes never changing resource dependencies. CCPM improves the project plan by aggregating uncertainty into buffers at the end of activity paths. In this research, one hundred twenty random projects were generated and analyzed using Microsoft Project software according to the traditional CPM and the CCPM once using the sum of squares (SSQ) method and another using the cut & past (C&PM) method. CCPM-SSQ method revealed an average savings of 13% and 43% in duration and cost, with a standard deviation of 21 and 11 for duration and cost respectively. While the CCPM-C&PM method revealed an average overestimation of about 2% in duration and 43% savings in cost, with a standard deviation of 25 and 11 for duration and cost respectively.