V Model


Software Development Life Cycle refers to all the activities that are performed during software development including- requirement analysis, designing, implementation, testing, deployment and maintenance phases. In this tutorial, we will refer to one of the most widely used SLDC model - V model.

V Model

V model is also known as Verification and Validation model. In V model, the testing phase goes in parallel with the development phase. Thus, the testing phase starts right at the beginning of SDLC.

V Model

As we can see in the above diagram, the test activities start in parallel with the development activities e.g. during the requirement analysis phase, acceptance-test cases are prepared by the testing team; during system design phase, the system test case are prepared. Similarly, for each phase of development a corresponding QA activity is performed. Later, when the deliverable gets ready, the QA artifacts are used to conduct the testing. Along with that, each phase of development phase is verified before moving to the next phase.

Advantages of V Model

  • Each phase of development is tested before moving to next phase, hence there is higher rate of success.
  • It avoids defect leakage to the later phases as each phase is verified explicitely.
  • The model has clear and defined steps. So, it is easier to implement.
  • It is suitable for smaller projects where requirements are fixed.

Disadvantages of V Model

  • The testing team starts in parallel with development. Hence, the overall budget and resource usage incerases.
  • Change in requirement are difficult to incorporate.
  • The working model of the software is only available in the later phases of the development.
  • It is not suitable for complex and large applications because of its rigid process.