Division of Labor: Web vs. Applications vs DBAs vs Systems

I manage the applications team in our shop. We frequently get tasked with implementing new applications for various busienss units. These apps have never had a home in our shop before so the question of who owns what frequently comes up.

I would love to hear about the specific duties for the Web team, DBA team, Applications team, and Systems (OS) teams with respect to where these respective duties begin and where they end. We constantly get into finger pointing sessions with the common theme being that’s not my job; the x groups should do that. What’s the right answer here?