What is the evidence supporting the PMBOK practices?

Question

The PMBOK (A Guide to the Project Management Body of Knowledge, 5th edition) states:

The PMBOK Guide contains the globally recognized standard and guide for the project management profession. [...] the knowledge contained in this standard has evolved from the recognized good practices of project management practitioners who have contributed to the development of this standard

My question is, what is the scientific evidence supporting the practices recommended by the PMBOK?

Answer 1

If you are trying to assess the scientific validity of the PMBoK, you will not get too far. The PMBoK is a body of knowledge and not even the complete body of knowledge. It is not prescriptive but rather descriptive. There is nothing to measure.

However, if you dig deeper into the practices, such as EV for cost control or critical path management of schedule control or Monte Carlo for estimation, you'll likely find varying degree of science behind their efficacy but you will find some support and validity. In other cases, I suspect you will find some practices to be more tribal in nature with anecdotal support but no science behind them.

Answer 2

In fact, the Project Management Institute has two monograph about the evidence associated to Project Management practices:

• Quantifying the Value of Project Management. The monographs shows that Project Management practices improve schedule and cost predictability.
• Researching the Value of Project Management. The monograph establishes a research program for the subject and provides some qualitative evidence about the benefits of the practices.

Unfortunately, the monographs has not gone through the typical journal peer-review process.