to work with developers and business analysts so they can perform these activities and tasks and produce a set of test deliverables. The work products produced by the developers and business analysts during development are the basis of testing in one or more levels. By starting test design early, defects are often found in the test basis documents. A good practice is to have testers involved even earlier, during the review of the (draft) test basis documents. The V-model is a model that illustrates how testing activities (verification and validation) can be integrated into each phase of the life cycle. With in the V-model, validation testing takes place especially during the early stages, e.g. reviewing the user requirements, and late in the life cycle, e.g. during user acceptance testing.