The system is split into modules which are designed one after the other and incorporated into the system as they are developed.

Waterfall and Prototyping deliver completely operational products.

This incremental model delivers operational quality products satisfying a subset of the users' requirements. There may be 10 - 50 builds. The user is up and going early.

Advantages

• Gradual change is incorporated
• Good cashflow
• Open architecture

• Integration problem
• Open architecture is needed
• Danger of reverting to build and fix