V-Model
The V-Model (Verification and Validation Model) is an SDLC model where testing activities are planned in parallel with development activities, forming a V-shaped structure.
- Left side → Verification
- Right side → Validation
1. Definition
The V-Model (Verification and Validation Model) is an SDLC model where testing activities are planned in parallel with development activities, forming a V-shaped structure.
2. Structure of the V-Model
Left Side (Verification Phases)
- Requirement Analysis
- System Design
- High-Level Design
- Low-Level Design
Right Side (Validation Phases)
- Acceptance Testing
- System Testing
- Integration Testing
- Unit Testing
Each development phase has a corresponding testing phase.
3. Mapping of Development and Testing Phases
| Development Phase | Corresponding Testing Phase |
|---|---|
| Requirement Analysis | Acceptance Testing |
| System Design | System Testing |
| High-Level Design | Integration Testing |
| Low-Level Design | Unit Testing |
4. Key Characteristics
- Testing is planned early
- Clear mapping between development and testing
- Emphasis on requirement traceability
- Defects are detected earlier than Waterfall
5. Role of Manual Tester in V-Model
During Requirement Analysis
- Review requirements
- Identify acceptance test scenarios
During Design Phases
- Prepare system and integration test scenarios
- Review design for testability
During Development
- Prepare detailed test cases
During Testing
- Execute planned test cases
- Perform regression testing
- Validate requirements
6. Advantages of V-Model
- Early test planning
- Clear traceability
- Reduced defect leakage
- Structured and disciplined approach
7. Disadvantages of V-Model
- Rigid and inflexible
- Changes are costly
- No early working software
- Not suitable for frequently changing requirements
8. When V-Model Is Suitable
- Requirements are stable
- Safety-critical or regulated systems
- Projects requiring high reliability
9. V-Model vs Waterfall
| Aspect | Waterfall | V-Model |
|---|---|---|
| Testing Planning | Late | Early |
| Verification | Limited | Strong |
| Validation | After dev | Mapped to each phase |
| Risk | Higher | Lower |
10. Real-Time Example
Medical devices, automotive software, and aerospace systems often use the V-Model due to strong validation requirements.
11. Common Mistakes
- Treating V-Model same as Waterfall
- Skipping early test planning
- Poor traceability between requirements and tests
12. Interview-Ready Answers
Short answer:
The V-Model is an SDLC model where verification and validation activities are planned in parallel with development.
Detailed answer:
The V-Model emphasizes early testing by mapping each development phase to a corresponding testing phase, ensuring defects are prevented and detected early.
13. Key Takeaway
The V-Model strengthens quality by integrating testing early and systematically into development.