5 ms·

I can. Do your estimation normally. If you've done it a dozen times multiply by sqrt(pi), if you've done it a couple of times multiply by pi, if you've never do

I can. Do your estimation normally. If you've done it a dozen times multiply by sqrt(pi), if you've done it a couple of times multiply by pi, if you've never done it before multiply by pi^2. I'm not off by more than 20%.

jacobolus 7y ago
Your heuristic that someone who has done a dozen previous software estimates will not take more than 177% of their current estimate to finish a “non-trivial software” project seems wildly optimistic to me. Consider that many software projects led by experienced software engineers go so far over time that they are never finished.
- buzzkillington 7y ago
  No, that's category 3, pi^2, or roughly 10 times the estimate. Category 1 is >I've written a script to get the data from tables 1 to 24 of this database, now I need to write one for table 25. It should take me an hour. >Oh look, it took me nearly 2 hours because I forgot that table is owned by a different user to all the other ones and I didn't have the right permissions.
  - jacobolus 7y ago
    So to clarify: what the top-level poster here is calling “non-trivial” you are calling “category 3”, and heuristically estimating that it will take 10x longer than anticipated. But this (a) is still quite optimistic, and (b) ignores variance. The potential time a new research project could take is unbounded.
    - meheleventyone 7y ago
      Yup, padding estimates is akin to what you might do if you had a repeatable process but there was some predictable variance (e.g. illness, machinery maintenance, holidays) rather than a bunch of unknown and exploratory problem solving.
      - TeMPOraL 7y ago
        You're almost never wandering into complete unknown. Your original estimate already encompasses your uncertainty; padding it protects you from optimism.
        meheleventyone 7y ago
        Right but the padding is basically an estimate of how certain you are about your uncertainty. So not only does the original estimate not encompass your own uncertainty but it's completely arbitrarily scaled by multiples of the original estimate. Which is rather to say the original estimate is completely useless. Not to mention the OP is never more than 1/5 of this greatly inflated estimate off!!! Whereas padding in a more assembly line like situation can actually be measured and forecast from historical data.
fastball 7y ago
How can you have an accurate estimate when you're multiplying it by 10? A small error in your original estimate gets multiplied by 10. If I'm off by 10 days in the original estimate, that means I'm off by 100 using your method. Also, I think by definition, a non-trivial project obviously hasn't been done by you many times before. Doing something you've done a dozen times is trivial in this sense.

jacobolus 7y ago

Your heuristic that someone who has done a dozen previous software estimates will not take more than 177% of their current estimate to finish a “non-trivial software” project seems wildly optimistic to me. Consider that many software projects led by experienced software engineers go so far over time that they are never finished.

buzzkillington 7y ago
No, that's category 3, pi^2, or roughly 10 times the estimate. Category 1 is >I've written a script to get the data from tables 1 to 24 of this database, now I need to write one for table 25. It should take me an hour. >Oh look, it took me nearly 2 hours because I forgot that table is owned by a different user to all the other ones and I didn't have the right permissions.
- jacobolus 7y ago
  So to clarify: what the top-level poster here is calling “non-trivial” you are calling “category 3”, and heuristically estimating that it will take 10x longer than anticipated. But this (a) is still quite optimistic, and (b) ignores variance. The potential time a new research project could take is unbounded.
  - meheleventyone 7y ago
    Yup, padding estimates is akin to what you might do if you had a repeatable process but there was some predictable variance (e.g. illness, machinery maintenance, holidays) rather than a bunch of unknown and exploratory problem solving.
    - TeMPOraL 7y ago
      You're almost never wandering into complete unknown. Your original estimate already encompasses your uncertainty; padding it protects you from optimism.
      - meheleventyone 7y ago
        Right but the padding is basically an estimate of how certain you are about your uncertainty. So not only does the original estimate not encompass your own uncertainty but it's completely arbitrarily scaled by multiples of the original estimate. Which is rather to say the original estimate is completely useless. Not to mention the OP is never more than 1/5 of this greatly inflated estimate off!!! Whereas padding in a more assembly line like situation can actually be measured and forecast from historical data.

fastball 7y ago

How can you have an accurate estimate when you're multiplying it by 10? A small error in your original estimate gets multiplied by 10. If I'm off by 10 days in the original estimate, that means I'm off by 100 using your method. Also, I think by definition, a non-trivial project obviously hasn't been done by you many times before. Doing something you've done a dozen times is trivial in this sense.