Many Teams must test more and more functionality in less and less time. Historically grown test suites are often not up to this challenge since they test too much and too little at the same time. Too much, since they contain redundant tests that post execution and maintenance costs but provide little value over similar tests. Too little since important functionality remains untested. In this talk, I present analysis techniques to uncover these problems in your own system: History analyses of the version control system show, where in the past most bugs occurred. Test gap analysis reveals, which code changes have not yet been tested. And pareto optimization of test suites and test impact analysis identify tests that right now have the best cost-benefit ratio. For each analysis, I outline the research foundation and give examples and experiences from application in practice.