Is the PMBOK® Guide descriptive?
It's common to say that PRINCE2® is prescriptive, while the PMBOK Guide is descriptive. I don't think so, though.
Both PRINCE2 and the PMBOK Guide are telling people what actions are correlated with success. One frames it as, "Do ______, if you want to be successful", while the other says, "Successful projects do ______" and implies that, "You probably want to do the same".
These are two sides of the same coin. A truly descriptive resource only tells you what's common in projects without judging what's right and what's wrong. That's not what people expect from their project management resources; they expect something that helps them be more successful. (And, of course, to learn what wrong ideas are popular, we have LinkedIn!)
Update 2025-09-11: After I reposted this article on LinkedIn on 2025-09-11, Bill Duncan, the [co]author of the first version of the PMBOK Guide, commented the following, which he had originally published in an article in PMI's PMNetwork:
The standards development community recognizes three major categories of standards:
- Descriptive standards. These are documents that tell the facts, details, or particulars of something. A document that described the characteristic symptoms of a flu sufferer would be a descriptive standard.
- Normative standards. These are documents that provide guidelines (norms) to be used as a basis for measurement, comparison, or decisions. A document that listed alternative approaches to treating the flu would be a normative standard.
- Prescriptive standards. These are documents that define a particular way of doing something. A document that specified a two week course of a specific antibiotic would be a prescriptive standard.
These distinctions help, but there is still room for confusion. For example, the first two chapters of the PMBOK Guide are primarily descriptive — they tell the facts, details, and particulars of certain aspects of project management. Chapters 3 through 12 are primarily normative — they provide a description of generally accepted knowledge and practice that you can use to measure your own. And the glossary was intended to be prescriptive — these are the definitions you should use, and if you use others, you should alert your fellow professionals to that fact.
Update 2025-09-15: This is a comment I gave to someone on LinkedIn, which may make my position clearer:
- Prescriptive means "you should do abc".
- I consider its synonyms prescriptive as well, such as "you'd better do abc".
- I also consider things that have the same purpose and practical consequence prescriptive, such as "if you want to be successful, do abc", or "those who do abc are more successful".
- A descriptive resource is one that says "some people do abc, some do bcd, and a few do cde".
In that sense, PRINCE2, the PMBOK Guide, and the instructions you get from your doctor for the pharmacy are all prescriptive.
Update 2025-09-15: I didn't explain why this topic is important. It's important because when we say that something is descriptive, we imply (correctly or incorrectly) that it's neutral, whereas when we consider it prescriptive, we accept that it's an opinion that might be correct or incorrect. Let's remember: The PMBOK Guide is not neutral. Also, a neutral, descriptive resource for project management is nearly useless.
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