When requirements are clear from the customer, but huge. Then the organizations can follow the incremental model to release the software instalment by instalment.
- From the above diagram in the first instalment (i #1) all the process from the software requirement gathering (SRG) to maintenance will be done and this will be proceeded up to last instalment (i # N).
- Thus finally all the huge requirement software will be developed and released to the customer instalment by instalment.
Advantages of Incremental model:
Generates working software quickly and early during the software life cycle.
This model is more flexible – less costly to change scope and requirements.
It is easier to test and debug during a smaller iteration.
In this model customer can respond to each built.
Lowers initial delivery cost.
Easier to manage risk because risky pieces are identified and handled during it’d iteration.
Disadvantages of Incremental model:
Needs good planning and design.
Needs a clear and complete definition of the whole system before it can be broken down and built incrementally.
Total cost is higher than waterfall.
When to use the Incremental model:
This model can be used when the requirements of the complete system are
clearly defined and understood.
Major requirements must be defined; however, some details can evolve with
There is a need to get a product to the market early.
A new technology is being used
Resources with needed skill set are not available
There are some high risk features and goals.