Ch 3. Agile SW Dev. - part 2: Agile Techniques (Extreme Programming)

A very influential agile method developed in the late 1990s introduced a range of agile development techniques. Extreme Programming (XP) takes an ‘extreme’ approach to iterative development, building new versions several times per day and delivering increments to customers every two weeks. All tests must run for every build, and the build is only accepted if tests succeed. Incremental development is supported through small, frequent system releases, and customer involvement means full‑time engagement with the team. People work through pair programming, collective ownership, and a process that avoids long working hours. Change is supported through regular system releases, and simplicity is maintained through constant refactoring of code. XP has a technical focus and is not easy to integrate with management practice in most organizations; consequently, while agile development uses practices from XP, the method as originally defined is not widely used. Key practices include user stories for specification, refactoring, test‑first development, and pair programming.