Incremental Model in Software Engineering

Incremental process model is also known as successive version model.

First, a simple working system implementing only a few basic features is built and then that is delivered to the customer. Then thereafter many successive iterations/ versions are implemented and delivered to the customer until the desired system is realized.

A, B, C are modules of Software Product that are incrementally developed and delivered.

Each iteration passes through the requirements, design, coding and testing phases. And each subsequent release of the system adds function to the previous release until all designed functionality has been implemented.

The system is put into production when the first increment is delivered. The first increment is often a core product where the basic requirements are addressed, and supplementary features are added in the next increments. Once the core product is analyzed by the client, there is plan development for the next increment.

When to use this

1. Funding Schedule, Risk, Program Complexity, or need for early realization of benefits.
2. When Requirements are known up-front.
3. When Projects having lengthy developments schedules.
4. Projects with new Technology.

Disadvantages

1. Requires good planning and design.
2. Total cost is not lower.
3. Well defined module interfaces are required.