Which PMBOK knowledge area does project management sit under?

I often ask my students, colleagues, professionals and other interested parties this simple question only to be met by silence and then a string of attempts to answer by randomly running through sections of the PMBoK. 99.9% of the time they fail to answer correctly with their first attempt.

Which of the 11 PMBoK knowledge areas does project management fall under and why?

Let's answer this by answering 2 questions.

1) Why did the profession and discipline of project management gain momentum and legitimacy last century even though projects have been around for thousands of years?

Many decades ago, people within organizations and businesses were asked to squeeze in the management and delivery of once-off unique initiatives called 'projects' in addition to their day-to-day operational responsibilities. That is, people from the Managing Director and VP levels and below in the organizational structure. A lack of awareness of alternatives, a lack of certified training and being time-poor meant that projects were either hand-balled to someone else who also lacked the skills and time as they often took second place to other more pressing operational matters and responsibilities or just failed to deliver anything at all (no surprises there!).

With these failures, some catastrophic, came the realization that project management as a science and discipline needed to become professional. Institutes and other courses starting popping up everywhere around the world as did University and TAFE (Technical School) courses.

2) Now to answer, which area of the PMBoK does 'project management'sit under?

Ask yourself, if I assign a complex, multi-resource project to a staff member and gave him a large budget to manage who had no project management credentials or experience and used nothing more than a pad and pen (no tools, spreadsheets, etc), what would I consider to be theirs and thus your chances of project success (or failure)?

Now ask yourself, if I instead assign a professionally trained and qualified Project Manager who has certification(s) or other more advanced qualification(s), etc. and is trained in the science of project management who then applies and follows this science e.g. a `methodology, processes, reporting and much more and thus knows how to manage projects successfully. Would this increase my chances (probability/likelihood) of success? I think the answer now is obvious.

Appointing a trained, certified, experienced and qualified Project Manager to projects who then applies project management disciplines and practices is one key strategy to use to mitigate the likelihood of project failure. Therefore, project management resides under RISK MANAGEMENT.

What do you think?