**Different Stack** Pattern The automated tests (also test frameworks) are implemented using a different software stack then the [SUT][1] uses. This will make it harder for developers to maintain the tests. I have seen web development teams needing to learn Java as an extra language, because the test team decided to us a Java testing framework without having the app developers involved. The testers where familiar with Java and not the PHP/JavaScript stack use by the other teams. - Demotivates developers to write, fix and or extend tests - Harder to maintain for a team - Extra setup to run the test local [1]: http://en.wikipedia.org/wiki/System_under_test