Many of the process models currently used can be more generally connected by the V-model where the “V” describes the graphical arrangement of the individual phases. The “V” is also a synonym for verification and validation.

The model is very simple and easy to understand. By the ordering of activities in time sequence and with abstraction levels the connection between development and test activities becomes clear. Oppositely laying activities complement one another i.e. serve as a base for test activities. So, for example, the system test is carried out on the basis of the results specification phase. The coarse view of the model gives the impressionthat the test activities first start after the implementation. However, in the description of the individual activities the preparatory work is usually listed. So, for example, the test plan and test strategy should be worked out immediately after the definition of the requirements. Nevertheless it can contribute very well to the structuring of the software development process.

The disadvantage of the model is the coarse division into constructive work (including the implementation) on the left-hand side of the “V” and the more destructive tasks on the right-hand side. Here also the impression may develop that, after the implementation phase, a ready product can be delivered. A planned-in removal of defects and regression test is not given.