Testing should be part of the development process from specification to maintenance

Testing should be part of the development process from specification to maintenance
One mark of a good product specification and/or software specification is that every requirement is testable and everything that should be tested should be listed as a requirement. In fact, the first draft of the test plan can and should be written alongside the specification. (The first draft of the user manual can and should be written at this time as well. It is a crucial part of the testing.)