Basically put, like me, Scott Ambler is a refugee from RUP. He is interested in "tailoring into" RUP and other "full-fledged" methodologies based on agile best practices.

His Agile Modeling (AM) Home Page is a dedicated explanation.

Seminal book: Agile Modeling .

A recent excerpt from the Agile Modeling mailing list sees Scott's position on single source information (i.e., capture requirements in acceptance tests rather than use cases) and on avoiding unnecessary documentation:

Posted by: "Scott Ambler"

Thu Oct 19, 2006 9:24 am (PST)

A couple of points regarding the portion of your post below:
1. If you single source information by capturing requirements in the form of acceptance tests then they serve at least double duty -- they form your requirements documentation and your acceptance testing documentation. Better yet, if you can generate test code from them, they're doing triple duty.
2. Update documentation, or better yet only write it, if it adds actual value to your overall effort. If something seems like busy work, they it pretty much is busy work. It doesn't matter if it's a use case, a feature description, or a scenario -- does having that information captured actually add value? Does keeping it updated add value? If it's not worth updating, it's likely not worth creating.

- Scott
Practice Leader Agile Development, IBM Methods Group