This is a difficult question to answer without some more information. Any paper on this would be frought with pits and traps, as you will invariably see below. Here are some questions which I normally ask with this question:
- To what degree of scope is your SCM effort (Middleware up? Infrastructure as well as code Mainframe/Midrange?).
- What is the level of capability of your development community - are they trained in SCM Practices?
- Do you have consistent approaches to SCM with Teams? Are you reinventing the wheel each time?
- Are we talking about an enterprise level SCM offering or just within a project/programme?
- Is an ALM implementation in place?
- Are the SCM tools automated and hooked intothe change management and requirements management systems?
- Is the SCM Effort predominantly code centric development or packaged development?
- Is it a mature service offering or is it just starting out? What are the hours of support? The list goes on.
What I can say is that in the midrange space, regardless of the tool, if the Service is mature, the developers are well enabled by the SCM Team (who are themselves of high quality), for a fully fledged set of SCM services, a ratio of up to 200 developers per SCMer is a great target bsed on standard business hours of operation. This is with a scalable engagement model into the development groups (Centralised and decentralised).