Using Continuous Integration to Reduce Project Friction

o you want to be agile, do you? You want to work in small increments and continuously deliver business functionality. You want to embrace change, even if that means taking on new requirements late in the game. But wait, won't that be dangerous? It doesn't have to be if you've got a solid Continuous Integration (CI) infrastructure in place.

Agile Development and Friction
Before digging deeply into Continuous Integration, let me talk first about how agile developers want to work in this brave new world, and some of the potential problems along the way. Agile development means working iteratively and incrementally to build a system one feature at a time. The development team slices each project into iterations—but don't think that this just means doing a series of mini-waterfalls, because in agile development the team does all the traditional phases of development and testing simultaneously. The goal of any given iteration is to complete a finite number of business requirements. Completion in this case means "done, done, done." In other words, the development team has coded the feature, it passes all its acceptance tests, it's signed off by quality assurance, and the customer has reviewed and approved the feature.