What is V-model ?
– V- model means Verification and Validation model.
– Each phase must be completed before the next phase begins.
– Testing of the product is planned in parallel with a corresponding phase of development.
V- Model Design and Flow-
V model has the different phases as shown in the above diagram.
Advantages of V-model:
- Simple and easy to use.
- Testing activities like planning test designing happens well before coding. This saves a lot of time. Hence higher chance of success over the waterfall model.
- Proactive defect tracking – that is defects are found at early stage.
- Avoids the downward flow of the defects.
- Works well for small projects where requirements are easily understood.
Disadvantages of V-model:
- Very rigid and least flexible.
- Software is developed during the implementation phase, so no early prototypes of the software are produced.
- If any changes happen in midway, then the test documents along with requirement documents has to be updated.
What is Spiral model?
- Spiral model is a combination of sequential and prototype model.
- This model is best used for large projects which involves continuous enhancements.
Spiral Model design and flow-
The spiral model has four phases.
- Planning phase
- Risk analysis phase
- Engineering phase
- Evaluation phase.
1. Planning Phase:
- Requirements are gathered and analysis.
- Doing feasibility study
- Developed the Requirements like ‘BRS’ that is ‘Business Requirement Specifications’ and ‘SRS’ that is ‘System Requirement specifications’.
2. Risk Analysis:
- To identify risk and alternate solutions.
- If any risk is found during the risk analysis then alternate solutions are suggested and implemented.
3. Engineering Phase:
- Development and testing of the software takes place in this phase.
4. Evaluation phase:
- Customers evaluate the software and provide their feedback and approval
Advantages of Spiral model:
- High amount of risk analysis hence, avoidance of Risk is enhanced.
- Good for large and mission-critical projects.
- Strong approval and documentation control.
- Additional Functionality can be added at a later date.
- Software is produced early in the software life cycle.
Disadvantages of Spiral model:
- Can be a costly model to use.
- Risk analysis requires highly specific expertise.
- Project’s success is highly dependent on the risk analysis phase.
- Doesn’t work well for smaller projects.