A Comparative Study of the Critical Chain and PERT Planning Methods: No Bad Human Behaviors Involved

Since 1997, Critical Chain Project Management (CCPM) method has received a lot of attention and hundreds of successful cases have also been reported and all claims that it is possible to rapidly achieve highly reliable on-time delivery (OTD) with short project lead time (PLT) in multi-project environment. The main reason that CCPM can achieve highly reliable OTD and short PLT in multi-project environment can be contributed to that CCPM makes good use of safety time imbedded in tasks by two changes: logistical change and bad human behaviors change. However, if no bad human behaviors involved, does the mere emphasis on logistical change contributed to the success of project time reduction and OTD improvement? This is the key question still remained. A comparative study of the critical chain and Program Evaluation and Review Technique (PERT) planning methods, no bad human behaviors involved, was performed in this study. The simulation results showed that in terms of mean project time, CCPM is no significantly better than PERT. However, in terms of plan reliability, CCPM achieve higher reliable than PERT did and this is the contribution of CCPM logistical change.