2.2. V Model¶
V Model is a development process with better mapping and sequential way of product development. You may read more about it in Wikipedia.

Basically, it means:
Specify/Document test scenarios as early as possible. Map them back to the original requirements.
When we map test scenarios back to the Requirements, the Requirements get clearer.
If its specified, eventually, it will definitely get implemented. And since it is implemented, it will get tested.
But still, tests are implemented after development.
Any late change in development implementation will also have a cascading effect on the test implementation.
V Model promotes a process of Vertical Traceability and Horizontal traceability.
- Vertical Traceability:
Each higher level requirement is broken further down to lower level requirement(s).
- Horizontal Traceability:
And, each requirement (at a given level) has a corresponding test at the same level.
Catch
As we see in V Model — Practice, there is more than what meets the eye.