Answer: You need to adopt both Scrum and XP together to get the full benefits of scrum.
Reasons:
The reasons are based on years of doing XP and scrum, and specifically on what I learned from Jeff Sutherland's talk (for the ACCU in London, May 2009)
- Scrum is a management technique - not necessarily a software production method. Some people use scrum in other domains e.g. preparing museum exhibitions and running religious institutions... so it has the mechanisms you need to make a multidisciplinary team deliver work adaptably in small increments.
- Scrum, originally included all the extreme programming practices. Jeff Sutherland actually said that he's never seen a scrum project achieve the higher orders of productivity measured for scrum without using the extreme programming practices.
- Scrum and XP both come from the same background - Object-oriented programming, specifically with Smalltalk. The programmers went off and developed XP whilst the management people created scrum. You need both aspects - development practices and management practices.
- The XP practices were deliberately removed from Scrum to make it easier to adopt. - Implementing the XP practices is hard and it's difficult to get them adopted quickly. Jeff actually said that Ken Schwaber removed the XP practices to help people get started with scrum. The danger now is that this minimal scrum has become all that people see and expect.
- Lots of non-technical project managers now teach scrum - but they don't have the skillset to teach XP
- Not all developers find the XP practices easy to adopt - they can be hard sell and it takes a few months rather than the 2 days it takes to establish basic scrum.
