In general , we have had our best results by switching teams around. There are a few areas where one developer has so much experience or knowledge that they tend to come back to that area whenever there’s more to do.
Sometimes this has worked well, usually when it is specialized domain knowledge that’s in question. We’ve had developers who have tried to stick with internal parts of the system, and by and large that works out less well. I suspect that it’s because it’s hard to build good systems tools if you don’t have to use them. In any case, if you have someone who is stuck on some area, it’s to your advantage and theirs to move them to something else: you’ll get cross-training in their specialty area, and you’ll keep everyone fresh.
As a general rule, in every iteration, move the person who has been on the team longer to a new area.
© 1997, 1998, Ronald E Jeffries
ronjeffries@acm.org
http://www.xprogramming.com