The V-model is a software development process that describes the relationship between each phase of the development life cycle and its corresponding testing phase.
The V-Model’s core principle is that project details increase as it moves from left to right over time, with no reversals. Iterations happen horizontally between the left and right sides of the letter ‘V.’ In information system development, it’s a variation of the waterfall model where development progresses downward on the left side of the ‘V,’ while testing moves upward on the right side. Horizontal lines in the ‘V’ show how development phases influence testing phases. Acceptance testing is based on requirements, system testing on requirements and architecture, integration testing on requirements, architecture, and interfaces, and component testing on requirements, architecture, interfaces, and algorithms.
History of the V-Model
The V-Model likely originated in the 1960s, with no public citations available. In 1979, Barry W. Boehm expanded on the Vee concept in software engineering, emphasizing verification and validation. He distinguished between the upper part of the Vee for validation and the lower part for verification, connecting them to requirements and specifications. The multilevel nature of systems in the Vee diagram wasn’t explained further. Boehm credited the “V-Chart” to personal communication from J.B. Munson of System Development Corporation in 1977.
Stages:
- Requirements Analysis.
- System Design.
- Detailed Design.
- Coding.
- Integration.
- System Testing.
- Acceptance Testing.
Pros of the V-Model:
- Strict structure and sequence.
- Built-in focus on testing and quality control.
- Clear requirement definition.
- Easily measurable progress.
- Improved communication between teams.
Cons of the V-Model:
- Risk of requirements becoming outdated.
- Not suitable for agile and fast-paced projects.
- Difficulty in making changes in later stages.
- High costs and increased development time.
- Not always suitable for large and complex projects.
