If you're like me, you'll have put down some number with some level of reasoning, but without any real analysis. You probably didn't ask yourself the following questions that the article poses:
"Oh, you don't know anything about bees? Well, this is an estimating task. Estimating is about predicting in the face of uncertainty and incomplete knowledge, so that's no bar. We estimate for unfamiliar software projects every day. You don't bother? Oh! How ever do you prioritize your set of possible tasks (that's a rhetorical question)? What do I mean by "average"? Now, that's a good question. Do I mean the "mean population of bees in a hive over time, taking a typical annual cycle into account"? Or do I mean "the mean, calculated from the total population of bees in England at a specific time, divided by the number of hives in England"? And anyway, what do I mean by "insect"? Should you include critters such as mites, pillbugs, and wasps that live on, in, or among the bees? Hang on! Bees are hive animals; arguably the queen and her workers and drones constitute a "single genetic individual," so should you just count the number of queens? And if the hive is on the point of swarming (May or June maybe), should you count the queens that leave to find a new hive?"
So for a start, you probably didn't go deep enough into analysis to provide the estimate. And when you did, you produced a simple number, not even a range.
The article really made me question my estimation process. It made me feel a bit stupid about the whole thing - surely I should be asking more questions when I'm asked for an estimate.
So what type of estimator are you? And what type of process do you follow when estimating development tasks?
- The Optimistic Estimator
You always think things will get done quickly and that there will be no problems along the way. But you always find yourself caught for time at the end.
- The Pessimistic Estimator
You always assume the worst case, even if it doesn't turn out that way. When you find that you have more time than you really need, you manage to fill it up anyway. (Although I'll admit, sometimes negative estimates still leave you stuck for time)
- The Iterative Estimator
You've found the perfect balance - you keep refining your estimates along the way, ensuring they get brought into the project plan accordingly. As well as knowing you'll have the right amount of time, you ensure that all spare time is used wisely.
For the record, I still classify myself under optimistic, but hopefully I'll get the balance right sometime soon.