- Incremental model as the name indicated produces many versions.
- Each version with a new functionality.
- In it whole requirements is divided into various builds.
- Each new build carry new functionality over previous build.
- It seems like a multi “Waterfall Model cycle”.
- In this each module passes through requirements, analysis, design, coding, testing, deployment, maintenance etc.
- A first working software is produced in first release of this model.
- Development of new builds continues until the complete system is released.
- In this whole product got ready step by step.
Following is the illustration of Incremental Model:
Advantages of Incremental Model:
- Generates working software quickly.
- More flexible.
- Less costly.
- Gives time to think new function.
- Able to fulfill all and the new requirements of end users without stopping application use.
- Easier to test and debug during smaller iteration.
- Customer can respond to each build.
- Easier to manage.
Disadvantages of Incremental Model:
- Total cost is higher than Waterfall model.
- Each new build requires with a new functionality.
- Requirements can go beyond the scope decided.
- Needs good planning and design.
When to use Incremental Model:
- When a new technology is being used.
- When there are some high risk features and goals.
- When there is a need to get the product early in the market.
- When some requirements can be evolve with time.
- When requirements of the system easily understood and well defined.