JoEllen West says that development shops must conduct thorough regression testing to mitigate the instances where a change to the codebase breaks a feature in the software. Iterative development, Unit testing, automated testing, continuous integration, and testing early and often are the more accepted design practices in regression testing. Regression testing can be either continuous or you can have a regression testing iteration at the end of every development cycle. West says it's also preferable to automate many regression tests, especially if you're using the continuous method. West concludes by explaining how a manager will know if their regression testing strategy is working.
JoEllen West is the Agile Tester on VersionOne's development team. She focuses a lot of her efforts on organizing and conducting regression tests.