There are 3 concepts in QA/QC (QA: procedures and certification, QC: actual testing works): Unit-test, auto-test, manual test. Unit-test Unit-test isn't good for regular quality or even to 80% quality (A grade) of programmes or services because it takes to much time that is equivalent to development time to test every piece of logic in programmes. This is the same as writing the same source code 1 more time. Unless it is about premium quality above A grade. Auto-test Auto-tests are good to s...