Tuesday, June 30, 2009

Ownership, Responsibility and Sharing.

Im a big fan of collective code ownership. This is my attempt to clear up one common point of confusion. Responsibility does not imply ownership. Making everyone responsible for the whole codebase most often fails miserably for the same reasons very few can keep any sufficently large system wholy in their heads. If everyone is responsible, most often nobody or a select few is. My current thinking about this is that people should be responsible for a slice of functionality or a module depending on your circumstances. But they're responsible, they don't own it. Anyone can, and should be encouraged to, change the code. The responsible guardian for that part should monitor changes, clarify conceptual missunderstandings, know his part of the system on a sufficent depth to be able to detect at a structural and conceptual level when duplication is creeping in to other parts of the system. Having responsibility does not mean soly working on that part, it means shepherding it and making sure that peers adhers to agreed conventions.

I've seen tremendous benefits from this, it lets people get really good at one part of the system, giving them both pride and the ability to at a much deeper level draw parallels to other parts during pairing sessions and work on other parts. It avoids the "everyone knows almost nothing about everything"-problem thereby reducing waste due to relearning and rediscovery. It sets expectations and builds team spirit, if we know that someone will be checking our work we tend to take greater care. And noone want to let a team-mate down. Theese effects augument conventional practices like pair programming in a very positive way.

Thursday, June 25, 2009