Simplified View of the Standard Waterfall

1. Install & Operate Test & Integration Requirements Design Implement Simplified View of the Standard Waterfall

2. Req’s Impl. T & I Design Req’s Design Impl. T & I Req’s Design Impl. T & I “Pure” Incremental Development Also known (more in the military than the civilian world) as PPPI, Pre-Planned Program Improvement ProjectPlanning increment 0 aka “Core System” increment 1 Increment 2 and so on • High level requirements or objectives or capabilities are assigned to increments at the start of the project • Each increment is a complete waterfall in and of itself, no planning for feedback from one increment to the next • Increment 0 is often the biggest and hardest - a basic operational system is usually bigger than any functional enhancement • Probably have to build/integrate OS, DBMS, networking package, etc • Probably have to develop pretty complete HMI

3. Evolutionary Development Review current Req’s Bucket; categorize items for risk and priority • Highest priority with acceptable risk, assign to current increment • “Medium” priority with acceptable risk, tentatively assign to some future increment • Low priority, low risk; leave in Req’s Bucket for future consideration • Unacceptable risk, assign to prototyping risk reduction prototyping low risk high risk standard waterfall customer concepts and documents Increment Planning Test Install & & Integ. Operate increment 0(a.k.a. MEC) Req’s Design Impl. customer feedback increment 1 Requirements Bucket customer feedback increment 2 customer feedback increment 3 customer feedback and so on

4. The Minimum Essential Core (MEC) • Imperative to keep increment 0 as small and simple as possible • Feedback process from real users can’t start until MEC is fielded • Basic philosophy – a feature or capability doesn’t go into increment 0 unless the customer is willing to say, “we won’t pay for the development without this” or “there’s no point in delivering such a system, it can’t be used by anyone for anything useful”