How can it be known when to stop testing?
Unfortunately, for any but the simplest software projects, it is nearly impossible to adequately specify useful criteria without a significant amount of assumptions and subjectivity. For example, if the release criteria is based on passing a certain set of tests, there is likely an assumption that the tests have adequately addressed all appropriate software risks. For most software projects, this would of course be impossible without enormous expense, so this assumption would be a large leap of faith. Additionally, since most software projects involve a balance of quality, timeliness, and cost, testing alone cannot address how to balance all three of these competing factors when release decisions are needed.
