Definitions on how to implement Sustainable Pace vary, though, from the dogmatic 40-hour rule to "whatever the team can sustain". For those unfamiliar with the concept, Ron Jeffries, an XP originator, has written:
Lacey goes on to say: "I used to get hung up on this and even today I continue to see others getting hung up on this. I used to think that I had to work at a sustainable pace and that I would fail if I worked overtime." He now understands it differently, and makes some suggestions on determining the value of overtime (rather than rushing ahead and doing it for the usual reasons) in his MSDN blog entry called Breaking the Rules of Agile - WorkingExtreme Programming teams are in it for the long term. They work hard, and at a pace that can be sustained indefinitely. This means that they work overtime when it is effective, and that they normally work in such a way as to maximize productivity week in and week out. It's pretty well understood these days that death march projects are neither productive nor produce quality software. XP teams are in it to win, not to die.
For more on why sustainability is important, read Ron Jeffries' Impact of Overtime on Productivity, which starts out with:
More features will always bring more revenue, more customer satisfaction, other good things. Therefore there is always pressure for people to work harder, longer hours. This is demonstrably a Bad Idea. Here's some evidence, and some ideas about how to know if pressure is too high.and along the way he covers topics such as these:
- Industrial Accidents and the Professional Programmer
- Mental Acuity for Programming
- Disproportionate Impact of Defects
- Practices Slide Under Pressure