Matt Cornell wrote a great post back in 2006 about how GTD is like Extreme Programming for time management. He named a number of ways in which GTD applies core XP idea: if it’s a good way to work, do it as much as possible.
But there are also a lot of direct correspondences between the XP process and GTD. My experience with XP is from working at Pivotal Labs, so I’m thinking specifically of Pivotal’s process when I make these connections:
We start a project by looking at the purpose of the project and the principles behind it, and from there extrapolate a vision of success (XP’s Inception process; David Allen’s Natural Planning Model).
We review the project weekly (XP’s Iteration Planning Meeting, Allen’s Weekly Review).
We don’t plan our the whole project in advance. In XP, we plan out a week’s worth of work at a time because it works best to plan when the whole team’s present, and the course doesn’t change too much in the middle of a week. As individuals, we can plan just the Next Actions for our Projects because we can easily plan the next Next Action when we’re done. In either case, we’re just taking the few steps we can see from where we are and holding a destination in mind, though the destination will change over time.
We throw all of the steps we’ve committed to into a single list (since there’s only one Context: development) and do the most important thing first. We order things in priority order in advance, but that’s because the person who determines the priority (the product manager) isn’t the person who’s doing the work (the developer). That’s what Doing should look like in GTD: don’t think about whether you should do it, just do it, and then do the next thing. You’ve already set aside time for thinking; this is your time for doing. Work in a state of mind-like-water.
And another correspondence: once XP becomes your development process, or GTD becomes your life process, it’s hard to imagine going back.