Incremental process model of software engineering provide, a limited set of software functionality to users quickly and then refine and expand on the functionality in later software release.
The product through iterative process model in SDLC , is decomposed into number of components, each of which is designed and build separately and deliver to the client when it is complete.
If modifications are required, it is to be done in next release through linear sequences or “increments” of software.
The incremental process model combines elements of the waterfall model applied in an iterative approach.
It delivers a series of releases called increments that provides progressively more functionality for the customer as each increment is delivered to the client.
Phases of incremental process model are as same like waterfall model, which carried out increments in each phases of -:
A] Requirement Gathering and analysis
First increment is core product that is, basic requirement is addressed, but many supplementary features remain undelivered.
As a result of use and evaluation, a plan is developed and delivered in next increment.
Through additional enhanced features and functionality, core product should be meeting and satisfy customer needs.
This process is repeatedly following the delivery of each increment, until the complete product is produced and delivered to the customer.
When it is used -:
– All requirements should be clearly understood
– Modifications are required early release
– While team resources are limited and not trained or skilled
Advantages of Incremental process Model -:
1] Progress and parallel development can be measured and planned
2] Easy to manage risk
3] Easy to test during each increments and regression testing should be conducted
4] Customer can respond to review the product for needful changes
Disadvantages of Incremental process Model -:
1] Cost may exceed because of incremental raised issues
2] Need to good understand, plan and design
3] More and skilled resource required