Prompted by a comment by Murray on my first blog in this debate I wanted to expand some of the ideas that have not yet been explored.
Here are the key excerpts from Murray's comment:
PMBOK V4 is compatible with and supportive of Agile processes. Here are some relevant quotes from CHAPTER 2 − PROJECT LIFE CYCLE AND ORGANIZATION
"There is no single way to deﬁne the ideal structure for a project"
"it is up to the project manager and the project management team to determine the most appropriate method of carrying out the project"
"There are three basic types of phase-to-phase relationships:
• A sequential relationship (...)
• An overlapping relationship, where the phase starts prior to completion of the previous one (...)
• An iterative relationship, where only one phase is planned at any given time (...)
The PMBOK v4 is quite recent and I have to admit I'm not familiar with it.
However, PMBOK v3 completely omitted the discussion about phase-to-phase relationship in the way described above.
Another aspect that is seldom discussed is that in IT projects (specifically Software Products) we are very quickly distancing our methods from the project-concept. In companies where I've worked, projects no longer represent in any meaningful way how the company works.
Another caveat is that Linear-iterative projects (like RUP proposed) are significantly different from the Incremental-iterative project structure that Agile methods in general and Scrum specifically propose.
All in all, there are significant differences that warrant a very skeptic look at what PMBOK has to offer.
If you want to check some other views into why the "project" pattern is not necessarily useful for software product development take a look at this blog post by Ari, who has quite a long experience in product companies: "Focusing on projects ruins your business"
Photo credit: Dunechaser @ Flickr