Incremental & Iterative Development Risk Mitigation

Some thoughts on where incremental & iterative development (IID) methods mitigate risks not provided by a waterfall approach:

• Risk-driven iterative development forces tackling the most complex and riskiest problems first.
• IID requires testing early on (even before coding), with tests being improved over iterations.
• Early visibility for clients into the interim and target product and therefore better feedback mechanisms to refine the functionality/capability. This is forced by continuous and formalized input and presence of clients during development.
• Performance risk profile of the application is improved by delivering tested software frequently.

Other thing I have noticed recently (not us!) is people building up a door stops' worth of functional specifications, and then looking to do agile development against that. Amatuers.