Sidebar: Beyond XP: Sabre's Development Methodologies

Computerworld - As enormously helpful as extreme programming (XP) is in the programming process, it shouldn't be seen as a complete software development methodology.
Sabre Airline Solutions has supplemented the 12 standard XP practices with two that deal with planning and five that are performed by a separate group for quality assurance and configuration management.
Here is Sabre's complete set of 19 software development practices, beginning with the 12 XP practices:

XP Planning Practices

• 1. Planning game: The "XP customer" defines the business value of features and uses labor estimates provided by the programmers to set priorities and schedules.


• 2. Small releases: Teams get a simple system working early and update it frequently in very short cycles.


• 3. On-site customer: An application subject matter expert stays in or near the programming lab all the time. He decides on and prioritizes product features, writes the stories for programmers and signs off on the results.


• 4. Sustainable pace: Programmers are encouraged not to work excessive overtime in order to remain fresh and alert.

• 5. Simple design: Code should be the simplest that can meet known requirements, and it should never be made more complicated in order to meet some hypothetical future need.


• 6. Test-driven design: Programmers write tests first, then write the code that is to be tested.


• 7. Refactoring: System design is improved throughout the development project. Software is kept simple, clean, maintainable and free of duplication.


• 8. System metaphor: Developers use a common system of names and a common system description that improves understanding and communication.

• 9. Pair programming: Programmers sit at terminals and write code in pairs. Pairs are re-formed frequently.


• 10. Continuous integration: Developers integrate, build and test the system many times per day.


• 11. Collective code ownership: All of the code belongs to and must be understood by all of the programmers.


• 12. Coding standards: Partly as a result of other practices, such as pair programming and collective ownership, programmers write code to the same set of standards.

In addition to following the XP practices, Sabre follows two sets of its own best practices. These fall into the following two groups:

Planning Practices

• Delivery project planning.


• Software change request management.

• Configuration management.


• Functional testing.


• System testing.


• Regression testing.


• Defect tracking.