XP Values

Five values sit at the top of XP‘s ladder of abstraction. They are not motivational decoration: they are the tiebreakers you use when the practices run out.

• Communication. Most problems on a team turn out to be someone knowing something and someone else needing it. Practices that raise bandwidth (sitting together, pairing, conversation over documents) all serve this.
• Simplicity. The most intellectually demanding of the five, because “what is the simplest thing that could possibly work” is a hard question, not a lazy one. It cuts against building for imagined futures.
• Feedback. The value the whole method is built to maximize. Every XP cycle, from the seconds of a failing test to the quarter, exists to shorten the gap between a decision and news about that decision.
• Courage. Beck pairs it deliberately with the others: courage alone is hazardous, courage plus communication is telling the truth about the estimate. Throwing away code, or saying a deadline will not be met, both live here.
• Respect. Added in the 2004 edition and the clearest signal of what changed between the two books. The first edition read as a technical program; the second opens by declaring XP is about social change.

The order matters less than the fact that there are five and they conflict. Simplicity and Communication pull apart when a design is clear to its author and opaque to everyone else. The values do not resolve the conflict, they name the axes you are trading along, which is the same job tension between test properties does in the testing half of this garden.

Signal: when someone proposes a practice change, the team argues about which value it serves rather than whether it is “agile”.

Sources

• Kent Beck with Cynthia Andres, Extreme Programming Explained: Embrace Change, 2nd edition (Addison-Wesley, 2004), chapter 4. The five values and the chapter structure are visible in the publisher’s free sample; chapter 1 there states the philosophy is “based on the values of communication, feedback, simplicity, courage, and respect.”
• Bill Wake, Overview of “Extreme Programming Explained, 2/e”: Respect is new in the second edition.