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by taeric 3120 days ago
But a timeline is of seriously limited value. You can't burn down on time. You can't combine time estimates. You can't work uncertainty into time estimates. The list could keep going.

I agree no estimation process is perfect. Nor do I think you should do comprehensive estimates on new work. However, the thing you want to know it's how much work there is. Not necessarily when you'd like to release a year from now.

Odds are high you have a deadline. So the incentive is high to keep the estimate below that line.
1 comments
newfoundglory 3119 days ago
Of course you can work uncertainty into time estimates.

That aside, the incentive is high to keep the amount of work planned below the amount of work that can be done before the deadline. It doesn't matter how many abstract units or concepts you use, that's what you want to know if you have a deadline.

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taeric 3119 days ago
Working uncertainty into time estimates still just gives you two sets of times to consider, with no way of knowing why you missed the low one and just if you will hit the high one. (Unless you do really wide bars on your estimates, in which case, the high bar is going to be worthless.)

That is, if you give me a high confidence and a low confidence estimate, how do I know why you missed it when the time passes? More, how "close" to making it were you? If you got half of the work you estimated done by that time, I'd know you were about halfway there. If the date just passed, all I know is that you didn't make it.

And I used "I" up there. But it is really even more personal. All you know is that you didn't make it. You literally don't have anything to learn there.

Contrasted with any work you do. Look back and quantify what you did. Not how long it took to do it.

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newfoundglory 3119 days ago
> If you got half of the work you estimated done by that time, I'd know you were about halfway there

And only 90% of the work remaining!

It sounds like you are imagining an estimate as a standalone number that isn't revisited or given more detail. If that's how you do it then of course you can't learn from it. It's supposed to be an ongoing process - if you said '3-6 months' when we started then after 2 months I'd expect a different answer. I'd also expect the initial estimate to be accompanied by an explanation that talks about the work to be done and which areas are causing uncertainty.

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