Testing Method- Iterative Model

What is Iterative Model?

1. Also referred to as the Spiral Model 2. Starts with a simple implementation of a small set of the software requirements and iteratively enhances the evolving versions until the complete system is implemented and ready to be deployed 3. Analysis is done just the same as with the Waterfall method 4. Home in on the software output through repeating requirements, analysis, development and testing phases 5. Starts with implementation of a subset of the software requirements and iteravely enhances the evolving versions until the full system is implemented 6. At each iteration, design modifications are made and new functional capabilities are added 7. Basic idea behind this method is to develop a system through repeated cycles (iterative) and in smaller portions at a time(incremental)

Iterative Model Cons

1. More resources may be required 2. Although cost of change is lesser but it is not very suitable for changing requirements 3. More management attention is required 4. System architecture or design issues may arise because not all requirements are gathered in the beginning of the entire life cycle 5. Defining increments may require definition of the complete system 6. Not suitable for smaller projects 7. Management complexity is more 8. End of project may not be known which is a risk 9. Highly skilled resources are required for risk analysis 10. Projects progress is highly dependent upon the risk analysis phase

Iterative Model Application

1. Requirements of the complete system are clearly defined and understood 2. Major requirements must be defined; however some functionalities or requested enhancements may evolve with time 3. There is a time to the market constraint 4. A new technology is being used and is being learnt by the development team while working on the project 5. Resources with needed skill set are not available and are planned to be used on contract basis for specific iterations 6. There are some high level risk features and goals which may change in the future

Iterative Model Pros

1. Some working functionality can be developed quickly and early in the life cycle 2. Results are obtained early and periodically 3. Parallel development can be planned 4. Progress can be measured Less costly to change the scope/requirement 5. Testing and debugging during smaller iteration is easy 6. Risks are identified and resolved during iteration and each iteration is an easily managed milestone 7. Easier to manage high risk part is done first 8. With every increment operational product is delivered 9. Issues challenges and risks identified from each increment can be utilized applied to the next increment