maximize each iteration

This post by Ron Jeffries caught my eye a few days ago: maximize each iteration. Over the last six months, my team has released a build to a customer at least once every two weeks, often more frequently. When I first started in this world, I was told, frequent checkins are good. At Brown, I would make a little tiny change, check it in, repeat over and over. Yes, I broke the build frequently, and my colleagues and I did not understand eachother's code at all. Here at Laszlo Systems, every checkin requires a peer code review. This is fantastic for code quality, but as usual there's a quality for time trade-off. In choosing the granularity at which to do checkins, I am starting to consider some of the hidden costs:

• The author needs to synchronize their tree, resolve any conflicts, and do some version of a fly-through/smoke-test.


• The author and the reviewer have to do the review at the same time, which means the author will some small-chunk time waiting for an available reviewer.


• After the review, the reviewer and the author will both have to re-establish their cognitive state.


• The other members of the team will have to update to get each checkin, and pay their integration tax. Each integration has a flat fee in addition to the per-line-of-code-change cost.

It's worth it. An ivy league education is essentially a long series of having really smart, experienced, knowledgeable people review one's work and suggest how to improve it. Even if it didn't improve software quality, the code reviews would be worth the time for the sheer educational value.
Ideas for how to improve the value of each code review:

• Do reviews in coordinated pairs. If we both wait until we're ready for a review, we only pay the stop/start cost once for two reviews.


• Take the right size bites. The XP metric is something like a day of work or less, I think; right now I'm feeling like two or three days would be better for my team's process. I need to stray farther from the trunk to maximize the value of each of my reviews. I think XP calls this courage.


• A lot of my checkins are (just) changing assets and constants. I should combine many low-risk changes into a single checkin.

Any other suggestions on how to maximize each iteration?