4 ms·
I've been told a good rule of thumb for producing reasonable estimates is to make an estimate for how long you think it should take, then double the answer and
by marksutherland 18y ago
I've been told a good rule of thumb for producing reasonable estimates is to make an estimate for how long you think it should take, then double the answer and add 10%. I never want to follow the advice when making estimates, as it feels like saying it'll take so much longer than I actually think it will might make it seem I'm inefficient, but in reality it turns out to be about right.
Perhaps also worth mentioning Hofstadter's Law:
"It always takes longer than you expect, even when you take Hofstadter's Law into account."
- jwilliams 18y agoDouble it is basically the engineering mantra -- The problem is when is occurs in big organisations and/or projects. The doubling can be compounded as the estimates trickle up. I've seen reasonable estimates of 10d suddenly explode into 40+d once it makes it into upstream project plans. Best thing to do is invest in metrics, and to revisit your estimates after the fact (nobody ever does this).
- nazgulnarsil 18y agoI've always gone with 4 times. That way even if it takes twice as long as I expected I still have plenty of time to either double check my work or goof off.
- swillden 18y agoI've jokingly suggested for years that the right approach is to make your best estimate, then multiply by pi. Not only does it boost the estimate enough that you're likely to hit the target, it also adds a lot of bogus precision to the numbers that the less-than-clueful will interpret as accuracy.
- misterbwong 18y agoI've seen another formula around and it has worked well for me in the past. It was presented to me at a project management session. It's basically a weighted average: (Best Case Scenario + Worst Case Scenario + (4 * Most Likely))/6