A snapshot of knowledge
When I pick up testing on a feature, my understanding of that area and the context in which it operates increases dramatically as I immerse myself into the testing of that area. For the period in which I am testing that feature, I am holding in my head far more information on it than if I was coming at it cold. As my understanding increases my exploratory tests improve and my ability to identify key tests to ensure the correct operation of that feature increases. If, at this point, I am able to encapsulate some of that knowledge into a set of automated tests, in essence I am capturing a snapshot of that elevated state of understanding. As I move onto other features my understanding of that feature will fade. The tests that I designed at the time will not. Well designed automation will repeatedly check aspects of the product that I thought were important at the time that I best understood that area and customer requirements that drove its development.
On many occasions I review test suites which focus on areas that I have not worked on in a while and find myself quietly impressed at the understanding of that area that I must have had at the time of creation.
There is an advert running in the UK at the moment for a vitamin supplement that claims to help you be you on a "really good day". I'm not suggesting that automation will ever replace the insights of a skilled tester, but a well designed test pack can capture small glimmers of that insight when at its highest to use to drive ongoing checks. You on lots of "really good days".
Copyright (c) Adam Knight 2011