Extreme Programming

Extreme programming (XP) is an example of such a trend. XP is an unorthodox approach to software development, and it has been argued that it has no design aspects. The extreme programming methodology proposes a radical departure from commonly accepted software development processes. There are really two XP rules: (1) Do a Little Design and (2) No Requirements, Just User Stories. Extreme programming disciples insist that "there really are no rules, just suggestions. XP methodology calls for small units of design, from ten minutes to half an hour, done periodically from one day between sessions to a full week between sessions. Effectively, nothing gets designed until it is time to program it."

Although most people in the software development business understandably consider requirements documentation to be vital, XP recommends the creation of as little documentation as possible. No up-front requirement documentation is created in XP, and very little is created in the software development process.

With XP, the developer comes up with test scenarios before she does anything else. The basic premise behind test-first design is that the test class is written before the real class; thus, the end purpose of the real class is not simply to fulfill a requirement, but simply to pass all the tests that are in the test class. The problem with this approach is that independent testing is needed to find out things about the product the developer did not think about or was not able to discover during her own testing.