The Art of Agile Development

About Values, Principles, and Practices

Values are ideals. They’re abstract, yet identifiable and distinct. For example, XP’s values are:

Courage

To make the right decisions, even when they’re difficult, and to tell stakeholders the truth when they need to hear it

Communication

To give the right people the right information when they can use it to its maximum advantage

Simplicity

To discard the things we want but don’t actually need

Feedback

To learn the appropriate lessons at every possible opportunity

Respect

To treat ourselves and others with dignity, and to acknowledge expertise and our mutual desire for success

Principles are applications of those ideals to an industry. For example, the value of simplicity leads us to focus on the essentials of development. As [Beck 2004] puts it, this principle is to “travel light.” [Cockburn] says, “Excess methodology weight is costly,” and “Discipline, skills, and understanding counter process, formality, and documentation.”

Practices are principles applied to a specific type of project. XP’s practices, for example, call for colocated teams of up to 20 people. Sit Together” in Chapter 6 and The Whole Team” in Chapter 3 embody the principles of simplicity because face-to-face communication reduces the need for formal requirements documentation.