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Estimates are difficult for developers and product owners

(thorsell.io)
225 points todsacerdoti | 1 comments | 07 Dec 25 19:17 UTC | HN request time: 0.241s | source
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yen223 ◴[07 Dec 25 20:01 UTC] No.46184611[source]▶
The unique thing about estimates in software engineering is that if you do it right, projects should be impossible to estimate!

Tasks that are easiest to estimate are tasks that are predictable, and repetitive. If I ask you how long it'll take to add a new database field, and you've added a new database field 100s of times in the past and each time they take 1 day, your estimate for it is going to be very spot-on.

But in the software world, predictable and repetitive tasks are also the kinds of tasks that are most easily automated, which means the time it takes to perform those tasks should asymptotically approach 0.

But if the predictable tasks take 0 time, how long a project takes will be dominated by the novel, unpredictable parts.

That's why software estimates are very hard to do.

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seviu ◴[07 Dec 25 20:12 UTC] No.46184700[source]▶
I am in a project where we have to give estimates in hours and days.

Needless to say we always underestimate. Or overestimate. Best case we use the underestimated task as buffer for the more complex ones.

And it has been years.

Giving estimations based on complexity would at least give a clear picture.

I honestly don’t know what the PO and TL gains with this absurd obscenity.

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121789 ◴[07 Dec 25 20:16 UTC] No.46184742[source]▶
Hours is insane. But ultimately time is money and opportunity cost. Software engineering can’t be the only engineering where you ask the engineers how much something will cost or how much time it will take and the answer is “it’s impossible to know”. Even very inaccurate estimates can be helpful for decision making if they are on the right order of magnitude
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yetihehe ◴[07 Dec 25 20:25 UTC] No.46184821[source]▶
I think software is one of those VERY rare things, where inaccurate estimates can actually be inaccurate by "orders of magnitude". After 20 years in the field, I still managed to use 2 months of time on a task that I estimated as 10 days.
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bumby ◴[07 Dec 25 21:08 UTC] No.46185166[source]▶
Something often overlooked in cost/schedule estimates is the nature of joint probability of actions slipping. Action A slips and causes action B to slip. I think software is tougher to estimate because the number of interfaces is often much higher, and sometimes more hidden, than in hardware.
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bdangubic ◴[07 Dec 25 21:15 UTC] No.46185226[source]▶
as opposed to say building a house where framing can totally slip while we run electricity and build a roof floating in mid-air

software is only tougher to estimate if incompetent people (vast majority of the industry, like 4+ million) is doing the estimating :)

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1. bumby ◴[08 Dec 25 13:30 UTC] No.46192005[source]▶
That’s a bit of a strawman considering I was deliberate in saying hardware interfaces are limited and not saying they are zero. The number of interfaces in software is often going to be orders of magnitude greater. The network effects and failure modes will often increase geometrically with the number of interfaces. In fact, big construction design firms have tools to easily identify and mitigate the “clashes” you bring up and those tools tend to work well because there is a finite number and the designs are well-documented (as opposed to software where changes are relatively cheap and easy so they often occur without documentation)

Saying incompetence is the reason is a trivial rebuttal that ignores the central claim about complexity. It’s like saying “the reason why we don’t have a theory of everything is because we don’t have competent physicists”