V-Model - UGC NET PDF Download

The V-Model, also known as the Verification and Validation Model, follows a structured and sequential approach in software development, similar to the Waterfall model. In this model, each phase of the Software Development Life Cycle (SDLC) must be completed before moving on to the next. One distinctive feature is that testing is planned in parallel with each development phase.

• Verification: This is a static analysis process, where the product is reviewed without running the code. It focuses on assessing whether the product development process meets the specified requirements.
• Validation: This is a dynamic analysis process that involves testing the software by executing code. The goal is to ensure the final product aligns with customer expectations and requirements after development is completed.

The V-Model is structured such that Verification phases are on one side, and Validation phases are on the other, with the coding phase connecting them in the shape of a 'V'. This structure gives the model its name.

Verification Phases in the V-Model:

• Business Requirement Analysis: This is the initial stage where the product’s requirements are understood from the customer's perspective. Detailed communication is key to accurately capturing the customer’s expectations.
• System Design: System engineers analyze the business needs of the proposed system based on the user requirements document.
• Architecture Design: In this phase, the overall system architecture is defined, detailing modules, their functionalities, interfaces, dependencies, database structures, and technology considerations. Integration testing is planned at this stage.
• Module Design: The system is broken down into smaller modules, and detailed designs for each module are created. This phase is often referred to as Low-Level Design.
• Coding Phase: After designing, coding begins. The appropriate programming language is selected, and code is written following specific guidelines and standards. The final build undergoes optimization and multiple reviews for performance before it is finalized.

Validation Phases in the V-Model:

• Unit Testing: Test plans for unit testing are developed during the module design phase. Unit testing checks that individual modules function correctly when isolated.
• Integration Testing: Test plans for integration testing are developed during the architectural design phase to ensure that independently created modules can work together.
• System Testing: System test plans are developed during the system design phase, typically by the client's business team, to verify that the application meets the intended requirements.
• Acceptance Testing: This phase corresponds to the business requirement analysis stage, testing the software in a real user environment. It checks compatibility with other systems and identifies non-functional issues such as performance and load handling.

When is the V-Model appropriate?

Advantages of the V-Model:

• Easy to understand.
• Testing phases, including planning and design, occur before coding begins, which can save time and increase the likelihood of success compared to the waterfall model.
• Helps prevent defects from propagating downward.
• Effective for small projects where requirements are clearly understood.

Disadvantages of the V-Model:

• Very rigid and inflexible.
• Not suitable for complex projects.
• Software is developed only during the implementation phase, so no early prototypes are available.
• Any mid-project changes require updates to test documents and other related documents.