The Automation Pyramid

Think about using the test automation pyramid when planning your test automation strategy.

The test automation pyramid was used by Mike Cohn to describe the value of different types of automated tests in the context of an ntier application. The concept is very simple. Invest more time and effort in those tests that are lower down the pyramid than those at the peak, as those tests lower down the pyramid provide the most value in terms of quick feedback and reliability, whereas those at the peak are expensive to implement, brittle, and time consuming.

The traditional pyramid is split into three layers, Unit testing at the base, integration/API tests in the middle layer, and UI tests forming the peak of the pyramid. Many now opt to describe the UI layer as the ‘end to end’ layer as this phrase better represents those types of test.

Useful posts on the subject:

http://martinfowler.com/bliki/TestPyramid.html by Martin Fowler

http://www.mountaingoatsoftware.com/blog/the-forgotten-layer-of-the-test-automation-pyramid
by Mike Cohn