Since the millennium bug there has been an explosion in test automation. The expansion of automated tools from vendors such as Mercury Interactive, IBM Rational, Segue and others has really delivered automated testing into the heart of just about every major organisation in the western world. And this can be seen to continue with new development methodologies such as eXtreme programming which has test automation at the heart of its design.

Automated tests can run much faster than the manual equivalent, so more testing can be achieved in a smaller time frame. It is not unusual to see regression suites that take two weeks manually reduced to 24 hours with test tools! Automated tests can be repeated over and over and will always perform the test exactly as recorded. Manual testers can easily make mistakes or perform the same test slightly differently when repeated.