Software testing earlier was an integral part of software development life cycle. Now even software testing is looked as a project by its nature itself. The life cycle of software testing is usually called as STLC Model and is popularly known as V-V Model.
V-V Model (STLC Model)
Just like the waterfall model, the V-V shaped life cycle is a sequential path of execution of processes. Each phase must be completed before the next phase begins. Testing is emphasized in this model more than the waterfall model. The testing procedures and developed early in the life cycle before any coding is done, during each of the phases preceding implementation.
Requirements begin the life cycle model just like the waterfall model. Before development is started, a system test pan is created. The test plan focuses on meeting the functionality specified in the requirements
The high-level design phase focuses on system architecture and design. An integration test plan is created in this phase as well in order to test the pieces of the software systems ability to work together.
The low-level design phase is where the actual software components as designed, and unit test are created in this phase as well.
The implementation phase is, again, where all coding takes place. Once coding is complete, the path of execution continues up the right side of the V where the test plans developed earlier are now put to use.
Advantages
- Simpe and easy to use.
- Each phase has specific deliverables.
- Higher chance of success over the waterfall model due to the development of test pan early on during the life cycle.
- Works well for small projects where requirements are easily understood.
Disadvantages
- Very rigid, like the waterfall model.
- Little flexibility and adjusting scope is difficult and expensive.
- Software is developed during the implementation phase, so no early prototypes of the software are produced.
- Model doesn’t provide a clear path for problems found during testing phases.
