Estimating feels good.
It makes us feel like we can control things, that we can whip both ourselves and time into shape. But I’ve found that life has a way of resisting being scheduled (dammit!)
Don’t get me wrong, I stand by the importance of estimating. If we don’t try to get a handle on the amount of time it takes to do something, we run the risk of getting totally off track. But we also have to paradoxically accept that we don’t know what we don’t know.
We don’t know what kind of family emergencies will arise to throw our schedules to the wayside, we don’t know that we may run into all sorts of technical problems setting up our new blog that we didn’t anticipate, and as disciplined as we may be one week, we may end up screwing around on Facebook for hours the next.
In their book Rework, 37 signals’ Jason Fried and David Heinemeier Hansson support the ‘breaking work into smaller chunks’ approach of estimating in a chapter bluntly titled ‘Your Estimates Suck.’ They point out that:
humans are just plain bad at estimating, which is why the Denver Airport opened 16 months late with a cost overrun of $2 billion dollars and Boston’s ‘Big Dig’ finished five years late.
So don’t be too hard on yourself if you’re estimates are off. It’s a bit of a paradox but that’s part of the process; we plan, God laughs.
Alas, we can’t control the future.
What we can do is break work down into more easily predictable (and over time, measurable) chunks and revisit our estimates on a regular (weekly, monthly) basis. The shorter the time span of the estimate (one week, versus four months) the more likely the estimate is going to reflect reality.