A Build Process is a set of (hopefully automated) steps to convert your software from source to deliverables.
Having a BuildProcess fully automated is in general a BestPractice, but it's absolutely vital when you're doing ContinuousIntegration (in XP or otherwise).
- Not only fully automated, but available to anyone. All developers should be able to (re)build the system, at any time.
-- KyleCordes
See also: UsingNmake, AntHill, CruiseControl, IntegrationGuard, ApacheAnt, NantTool