What is Iterative Model?
The Iterative Model is a software development methodology where the process is broken into small, manageable cycles or iterations. Each iteration includes a subset of the software’s functionality and goes through the stages of planning, design, implementation, testing, and evaluation. This approach allows for gradual development and refinement of the software, incorporating user feedback and addressing issues as they arise.
Key Characteristics of the Iterative Model
- Cyclic Process: Development progresses in repeated cycles, with each iteration building on the previous one.
- Incremental Delivery: A part of the software is developed and delivered in each iteration.
- Flexibility: Changes and refinements can be made in subsequent iterations based on feedback.
- Risk Management: Early iterations focus on addressing high-risk aspects of the project.
Phases of the Iterative Model
Each iteration typically includes the following phases:
1. Requirement Analysis
- Identify and prioritize requirements for the current iteration.
- Define what functionality will be developed.
2. Design
- Create a design plan specific to the features of this iteration.
- Update the overall system architecture as needed.
3. Implementation (Coding)
- Develop the selected features or components.
- Focus on a subset of functionality instead of the complete system.
4. Testing
- Test the implemented functionality for defects and issues.
- Conduct integration testing to ensure compatibility with previous iterations.
5. Evaluation
- Review the iteration with stakeholders and gather feedback.
- Refine requirements and priorities for the next iteration.
6. Deployment (Optional)
- Deploy the software if it is ready for production or as a beta release.
Advantages of the Iterative Model
- Early Feedback: Stakeholders can review and provide input after each iteration.
- Flexibility: Requirements can evolve and adapt during the project lifecycle.
- Risk Reduction: High-risk issues are addressed early, reducing the overall project risk.
- Incremental Progress: Deliverable software is produced early and updated in each cycle.
- Better Resource Utilization: Allows gradual allocation of resources as the project progresses.
Disadvantages of the Iterative Model
- Complexity: Managing multiple iterations and integrating components can be challenging.
- Time-Consuming: Frequent testing and review cycles may require significant time.
- Dependency on Feedback: Delays in stakeholder feedback can slow down progress.
- Cost: Iterative development may increase costs due to repetitive processes.
When to Use the Iterative Model
- Projects where requirements are not clearly defined at the start.
- Complex projects requiring risk management and early prototyping.
- Applications with rapidly changing needs or user feedback.
- Large-scale systems where incremental delivery is beneficial.
Example of the Iterative Model in Action
Developing a hotel booking system:
- Iteration 1: Basic functionality like searching and booking rooms is implemented and tested.
- Iteration 2: Additional features like user registration and payment integration are developed.
- Iteration 3: Advanced features like discounts, reviews, and customer support are added.
- Final Iteration: Refine and optimize all components based on feedback and testing.
Each cycle builds upon the previous, refining the system and adding value at every stage. This makes the Iterative Model particularly effective for projects requiring flexibility and ongoing improvement.
