Evolutionary Development, Waterfall and Change

Title: Evolutionary Development, Waterfall and Change
Type: Principles
Status: final
Version: 2007-07-10
Gist: Explain which conditions make a case for evolutionary development.
Source: Scott Selhorst on http://tynerblain.com/blog/2007/07/09/enabling-and-resisting-change/
Find a less brief description of Evolutionary Development here. http://kw-agiledevelopment.blogspot.com/2007/06/scrum-agile-development-uncommon-sense.html

P1: Evolutionary Development can very briefly described as:
Decide what needs to be done.
Do the most important things first.
Release the product incrementally as you complete items.
Re-evaluate and repeat.

P2: Waterfall Development can very briefly described as:
Decide what needs to be done.
Do things in an efficient sequence.
When finished, release the product.

Note: Kelly Waters descibes waterfall as: "Seeking to complete *everything* before releasing *anything*."

P3: There are at least 3 types of change where, if they occur, evolutionary development is better in handling than waterfall development.
Change in business needs (less frequent, large change each)
Change in requirements (frequent, medium change each)
Change in business rules (more frequent, small change each).