Buffer sizing methods of critical chain based on Parkinson's law

Considering the effect of Parkinson's law on human psychological behavior, a new assumption of activity completion time in critical chain project scheduling was proposed. Based on this assumption, the project buffer setting method by considering average time deviation and the feeding buffer setting method by considering parallel relationship were designed. Project buffer size determined by the new method was greater than that of Root Square Error (RSE) method, but the feeding buffer size of this method was smaller than that of RSE method. The simulation results showed that the new project buffer setting method could provide more reliable security time for the project. Besides, adopting smaller feeding buffer sizes would not cause any significant influence on the project duration.