Emergent Design

One of the most common points of extreme contention I find between Agile and Waterfall practitioners involves a heated debate about the appropriate time in the project’s life cycle to be making important decisions about the software’s architecture. In one corner, we have the Waterfall approach of Big Design Up Front (BDUF), and in the other corner we have the Agile approach of Emergent Design. I’d like to outline some of the key differences between the two design philosophies because I think the right choice becomes obvious when they’re contrasted appropriately.