XP and Software Quality
The use of XP engineering practices within the project was found to cause a marked improvement in the quality of the code, in comparison to previous projects. Although each of the practices addresses different aspects of code quality, they were found to have a profound overall effect over a period of time. Part of the reason is the incremental fashion in which they were applied. By gradually improving the existing code base while working toward the final solution, the code base gradually converges on an elegant and workable solution.
In summary, the application of XP engineering practices outlined above directly resulted in an increase in the quality of the completed code and test suites.