Dekker (2011) describes the drift into failure when mechanical or electronic equipment begins to exhibit stress and fatigue that is not identied by normal maintenance procedures. When a part in a plane, train or control system fails, it can come as a complete surprise, and often the failure is blamed on human operator error when really it should be regarded as design error or maintenance error. We could blame human error by designers, or human error by maintenance crew, but in reality, the end user, the operator, is often the rst to be blamed instead of the last. This person is a convenient scapegoat.