V-model

The V model (V-shaped validation & verification model) is a modified version of the waterfall model.

The V model is a model where the execution of processes happens in a sequential manner in a V shape. In the V Model, testing phases are related to corresponding development phases [Koomen 2006]. This means that for every single phase in the development cycle, there is a directly associated testing phase. This is an n to m relationship. In the V model, the corresponding testing phase of the development phase is planned in parallel. When you want to apply the V model, you may consider the following characteristics (this is not an exhaustive list):

• In this model the result of the current step is verified before proceeding.
• The product resulting from every phase needs to be checked and approved against products form preceding phases before moving forward.
• Teams are multi-disciplinary or tasks are performed by specialized teams, both meaning every task is done by a separate specialist, e.g. a person with the function of developer and another with the function of tester.
• The developer and tester work in a parallel manner.
• In the V model, the relationships between development stages and testing stages are given.