Extreme Programming

Extreme Programming (XP) is a method or approach to software engineering and the most popular of several agile software development methodologies. It was formulated by Kent Beck, Ward Cunningham, and Ron Jeffries. Kent Beck wrote the first book on the topic, Extreme programming explained: Embrace change, published in 1999. The second edition of the book, which appeared in 2005, delves more into the philosophy of Extreme Programming and describes it as being:

Goal of XP

The main aim of XP is to lower the cost of change. In traditional system development methods (like SDM) the requirements for the system are determined at the beginning of the development project and often fixed from that point on. This means that the cost of changing the requirements at a later stage in the project—not unthinkable in a rapidly changing business—will be very high. This concept is illustrated by the graph below.

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XP sets out to lower the cost of change by introducing basic values, principles and practices. By applying XP, a system development project should be more flexible with respect to changes. The graph below illustrates the intent to hem in the cost of change.

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