How Extreme Programming Enables Our Missile to Hit the Target

The features enabling a missile to track and hit a moving target are powerful thrust, low inertia, good sensors, and an effective feedback control system, able to both minimize the distance between the missile and the target and avoid instabilities.

XP is based on four values and 12 practices. These are the four values, viewed from the perspective of our metaphor.

• Simplicity A way to keep the missile's inertia low.

• Communication With the customer, it enables accurately defining the customer's requirements. Among developers, it enables spreading information about the development status, issues, risk, and problems. Communication is at the heart of the sensors and control system of our missile.

• Feedback The mechanism to manage requirement changes and keep the missile on track.

• Courage A consequence of the other values. We may consider it the ability to proceed at maximum speed, trusting that our missile will not deviate from its trajectory and will not explode on its course.

The 12 practices of XP are planning game (with user stories and engineering tasks), short cycles, metaphor, simplicity, refactoring, continuous testing, pair programming, collective code ownership, continuous integration, 40-hour week, on-site customer, and coding standards.

Also "The documentation is the code" and "Split business and technical" are key XP practices, even though not explicitly mentioned among the 12.

Let's now examine these practices from the perspective of the missile metaphor.