I got a fitbit bracelet the other day. It’s a pretty nifty gadget. It tracks the number of steps that I take in a day, as well as measuring movement while I’m asleep. I’ve been very impressed with the number of things that you can derive from a simple measure of the frequency of movement. You get number of steps, activity level, calories burned, sleep periods, and a few other metrics. All of that from one simple measure of how often my hand moves. Admittedly, some of those measures are inferred based on some simple assumptions like how many calories that the average person burns in a fixed period of time. However there is nothing wrong with that, The measure doesn’t have to be 100% accurate in order for it to be useful to me. I can see the trends and understand if my calories burned is changing for the better or for the worse without having the exact number of calories that I burn in an hour. An approximation is certainly sufficient.
It’s really quite impressive that you can derive so much from a single metric. It made me wonder about the metrics that we keep on Agile teams. Whether it’s velocity or throughput, there are metrics that we use for a lot of different purposes. We use velocity to tell us how much work the team can take on per sprint. We derive duration using velocity. I like the notion of having a small set of metrics like velocity that we can use for a variety of measures.