4 ms·

> "here's when we think it'll be done, but sometimes shit happens and there'll be a delay" I agree that a statement like that would not be useful. What I am sa

> "here's when we think it'll be done, but sometimes shit happens and there'll be a delay" I agree that a statement like that would not be useful. What I am saying is that it's better to make a good effort at estimation but then keep the stake-holders informed about what is going on, about the challenges and the mid-project delays. Any "95%" confidence calculation is kinda dubious. It would only work if you have meticulous and accurate records, have a long-enough history of delivering the same kind of product with the same team, the same customer-base, and the same tooling, oh yeah, and everyone has the psychological safety factor to be honest. If you work in a place where that exists, more power to you, but I think that's rare.

kqr 6y ago
I think I can work out a 95 % estimation I am willing to stake money on even without the things you mention. It does take good management/culture, but if I don't even have that, I'm headed for the dumpster anyway and should go home and rethink the whole thing first. > What I am saying is that it's better to make a good effort at estimation But what does that estimation mean? If we don't know after the fact whether the estimation was good or bad, then it's useless because it's an answer to an unknown question, and every stakeholder will interpret it differently. In order to know after the fact, we must know ahead of time whether we're aiming for 50 %, 90 %, or something else.
- crispyambulance 6y ago
  > I think I can work out a 95 % estimation I am willing to stake money on even without the things you mention. I doubt it. It's dicey to do estimations even when everything is well understood, but if you lack detailed and accurate records of past work for very similar projects... the best you can do is pad like crazy, cross your fingers, meet the deadline and say your confidence interval calculation was "accurate."
  - jbay808 6y ago
    If the lognormal distribution is correct, the 95% confidence interval is a bit over 5 times the developer's gut-feeling estimate. The 99% confidence interval is 10 times the developer's gut-feel estimate. We found a lot of data to back this up, but your mileage may vary.

kqr 6y ago

I think I can work out a 95 % estimation I am willing to stake money on even without the things you mention. It does take good management/culture, but if I don't even have that, I'm headed for the dumpster anyway and should go home and rethink the whole thing first. > What I am saying is that it's better to make a good effort at estimation But what does that estimation mean? If we don't know after the fact whether the estimation was good or bad, then it's useless because it's an answer to an unknown question, and every stakeholder will interpret it differently. In order to know after the fact, we must know ahead of time whether we're aiming for 50 %, 90 %, or something else.

crispyambulance 6y ago
> I think I can work out a 95 % estimation I am willing to stake money on even without the things you mention. I doubt it. It's dicey to do estimations even when everything is well understood, but if you lack detailed and accurate records of past work for very similar projects... the best you can do is pad like crazy, cross your fingers, meet the deadline and say your confidence interval calculation was "accurate."
- jbay808 6y ago
  If the lognormal distribution is correct, the 95% confidence interval is a bit over 5 times the developer's gut-feeling estimate. The 99% confidence interval is 10 times the developer's gut-feel estimate. We found a lot of data to back this up, but your mileage may vary.