The V - model is a model where execution of
processes happens in a sequential manner in V-shape. It is also known as
Verification and Validation model.
V - Model is an extension of the waterfall model
and is based on association of a testing phase for each corresponding
development stage.
So there
are Verification phases on one side of the .V. and Validation phases on the
other side. Coding phase joins the two sides of the V-Model.
Verification Phases
Following are the Verification phases in V-Model:
· Requirement Analysis: This phase involves detailed communication
with the customer to understand his expectations and exact requirement. This is
a very important activity and need to be managed well, as most of the customers
are not sure about what exactly they need. The acceptance test design planning
is done at this stage as business requirements can be used as an input for
acceptance testing.
·
System Design: System design would comprise of
understanding and detailing the complete hardware and communication setup for
the product under development. System test plan is developed based on the
system design. Doing this at an earlier stage leaves more time for actual test
execution later.
·
Architectural Design: Architectural specifications are
understood and designed in this phase. Usually more than one technical approach
is proposed and based on the technical and financial feasibility the final
decision is taken. System design is broken down further into modules taking up
different functionality. This is also referred to as High Level Design (HLD).
· Module
Design: It is important
that the design is compatible with the other modules in the system architecture
and the other external systems. Unit tests are an essential part of any
development process and helps eliminate the maximum faults and errors at a very
early stage. Unit tests can be designed at this stage based on the internal
module designs.
Coding Phases
The actual coding of the system modules designed in the design
phase is taken up in the Coding phase. The best suitable programming language
is decided based on the system and architectural requirements. The coding is
performed based on the coding guidelines and standards. The code goes through
numerous code reviews and is optimized for best performance before the final
build is checked into the repository.
Validation Phases
Following are the Validation phases in V-Model:
·
Unit Testing: Unit tests designed in the module design
phase are executed on the code during this validation phase. Unit testing is
the testing at code level and helps eliminate bugs at an early stage, though
all defects cannot be uncovered by unit testing.
· Integration Testing: Integration testing is associated with the
architectural design phase. Integration tests are performed to test the
coexistence and communication of the internal modules within the system.
·
System Testing: System testing is directly associated with
the System design phase. System tests check the entire system functionality and
the communication of the system under development with external systems. Most
of the software and hardware compatibility issues can be uncovered during
system test execution.
· Acceptance Testing: Acceptance testing is associated with the
business requirement analysis phase and involves testing the product in user
environment. Acceptance tests uncover the compatibility issues with the other
systems available in the user environment. It also discovers the non functional
issues such as load and performance defects in the actual user environment.