Agile methodology

Has anyone implemented an agile development cycle using Siebel?  If so, how did you work around the challenge of working in tools and source code controlling the many releases that may be moving into production?  The idea we have is to use our source code control SW to baseline each individual object (Applets, BC, BS, Links, etc).  That solves the baseline need of what is being introduced to production.  However, we still need to solve the question of where is the developer(s) unit testing?  Of course we will test locally but we have a best practice to also test in the