The V-model is another variation of waterfall development that pays more
explicit attention to testing. As shown in Figure 2-4, the development process pro-
ceeds down the left-hand slope of the V, defining requirements and designing system
components. At
the base of the V,
the code is written. On the upward-sloping
right
side of the model, testing of components, integration
testing, and,
finally,
acceptance
testing are performed.
A
key
concept of this model is that as requirements
are specified and components designed,
testing for those elements is also
defined.
In this manner,
each level
of testing is clearly
linked
to a part
of the analysis
or design phase, helping to ensure high quality and relevant
testing and maximize
test effectiveness.