V-Model

The V-Model is a software development methodology that visualizes the entire development process in a V-shaped sequence. Unlike the linear Waterfall model, the V-Model emphasizes that a corresponding testing phase exists for every development phase. This approach ensures that the verification and validation of a product are planned from the very beginning of the project, helping to catch defects early.

The left side of the V-shape represents the development phases, while the right side represents the corresponding testing phases.

Example: During the Requirements Analysis phase (left side), the team creates a detailed requirements document. The corresponding testing phase is Acceptance Testing (right side), where the software is ultimately tested against these exact requirements. Similarly, System Design (left side) is linked to System Testing (right side). A developer writing code would perform Unit Testing (right side) on their individual modules. This direct relationship between development and testing ensures that a plan to verify each phase is established proactively.