←back to thread

225 points todsacerdoti | 1 comments | | HN request time: 0s | source
Show context
yen223 ◴[] 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.

replies(19): >>46184700 #>>46184806 #>>46184873 #>>46184947 #>>46185145 #>>46185627 #>>46185768 #>>46185915 #>>46185952 #>>46186292 #>>46186318 #>>46186774 #>>46187054 #>>46187512 #>>46188101 #>>46189271 #>>46189483 #>>46196595 #>>46201725 #
vegetablepotpie ◴[] No.46185768[source]
As a project manager, it sounds like you're making excuses. Just give me a number, trust your gut!

We have a fundamental failure to communicate, what we're doing. The game project managers and finance believe we're all playing is a regression towards the mean, where everything is additive and rounds up to nice consistent formulaic sums. Whereas software development follows power law distributions. A good piece of software can deliver 10x, 100x, or 1000x the cost to produce it (ex: distribution, cost of delivering another copy of software is near 0 once written). You don't get that sort of upside with many other investments. Finance is happy with an NPV 8% above what they invest in. This means that when software people talk, everything they say sounds foreign, and everyone assumes it's because of jargon. It's not. The fish don't know they're swimming in water. When the fisherman comes, everyone is caught off guard.

So we get what the author talks about

> The estimates stopped being estimates. They became safety railings against being held accountable for unreasonable expectations.

We. Pad. Like. Crazy. Yes this is inefficient. Some project managers recognize this. We get theory of constraints. But rather than cull the layers of hierarchy that lead to the padding in the first place, all the blame for failure goes back to developers. Get hit on the head enough and you will stop acting in good faith and pad to save your ability to feed and cloth yourself.

replies(2): >>46185843 #>>46185892 #
Trasmatta ◴[] No.46185892[source]
> As a project manager, it sounds like you're making excuses. Just give me a number, trust your gut!

If we're just making up numbers, why don't you just make it up yourself and save the developers the trouble?

replies(1): >>46186043 #
vegetablepotpie ◴[] No.46186043{3}[source]
Ah! But I want you to own it. If you say it first... you own it. And I do not have to get you to agree to it.
replies(2): >>46186434 #>>46186487 #
1. ◴[] No.46186434{4}[source]