John Smith, Rational Strategic Services Organization, International Branch. All Rights Reserved.
A PDF version of this
article is available, however, you must have Adobe Acrobat installed to view it. You can download this and other RUP white papers from the IBM Web site.
Labeling RUP as heavyweight and XP as lightweight without further qualification does both a disservice by obscuring
what each is and what each was intended to do. And, when done in a pejorative way, it's simply meaningless posturing.
It is the implementations of these as processes that will be either "heavyweight" or "lightweight", and they should be
as heavy or light as circumstances require them to be.
XP is not a free form, anything goes discipline-it focuses narrowly on a particular aspect of software development and
a way of delivering value, and is quite prescriptive about the way this is to be achieved.
RUP's coverage is much broader and just as deep, which explains its apparent "size". However, at the micro level of
process, RUP occasionally allows and offers equally valid alternatives, where XP does not; for example, the practice of
pair programming, which is required by XP. This is not intended as a criticism of XP; simply an illustration of how XP,
as its name implies, has narrowed its focus.