It is important to do this in the context of the Services Life Cycle and did publish a short presentation on this topic a couple of months back. This presentations is a summary of the SOA Practitioners Guide Part 3: Introduction to Services Life Cycle with the addition of the IT Engagement Model slide (14) shown below.

This is the RACI (Responsible, Accountable, Consulted and Informed) slide listing all the roles and responsiblities of various actors across the services lifecycle. This is pretty generic in nature and could also be applied to non-SOA lifecycles too.
You comments are always welcome and do feel free to drop me line.
- Yogish Pai