[lazyasciiart]

I'm not a nuclear aircraft carrier refueller, so maybe the domain is different in a way I don't understand, but it's ridiculous to need a five year plan to just refuel something, people refuel cars in five minutes everyday.

I simply do not accept that it is impossible to refuel in a week or so, assuming it's a couple orders of magnitude more complex than refueling a car.

Thats about how your comment sounded.

[kryogen1c]

+1

However, your comment didnt help me understand. It doesnt help because even if i embark on something i have no idea about, even in total ignorance i can _bound the problem_.

I dont understand how a professional coder can approach even a problem and have no idea - you have to DO the problem, so what is your approach? Just start coding and somewhere between 5 days and 5 years you stop?

Planning meetings dont happen in a vacuum, so what kind of problem can you research but have literally no guess about its solution? Bear in mind, we're not talking edge cases (research grants or whatever), but coders hired to do a job.

[rramadass]

>i can _bound the problem_

This is the nub of the problem when it comes to software. I understand your skepticism but software development is really very different from other activities. It is "mind-stuff" (and thus quite unstructured) which needs to be expressed in very precise language to solve an [almost always ill-defined/constantly redefined] problem. The inherent complexity involved is huge due to the number of degrees of freedom and malleability involved.

I can do no better than point you to the article "The Humble Programmer" (http://www.cs.utexas.edu/users/EWD/transcriptions/EWD03xx/EW...) written by one of the pioneers of Computer Science to really understand the issues that make Software Development such a complex and difficult activity. And since then (the article is from 70's) we have made matters exponentially worse by orders of magnitude.

[thwarted]

The top answer to "Why are software development task estimations regularly off by a factor of 2-3?" on quora is a great analogy.

https://www.quora.com/Why-are-software-development-task-esti...

[mdpopescu]

Here's an analogy.

The spell for floating an object is Wingardium Leviosa. It usually takes an 11-year old a few days to become proficient at it.

Please give an estimate for a modification of this spell that will make the object lift, complete two vertical circles (720 degrees) and then go back to the starting point.

(Before you ask: yes, we're doing magic. We're combining words in specific ways to create significant effects in the world.)

[jdlshore]

Software development is filled with fractals. To do A, you break it down into A1, A2, and A3. To do A1, you break it down into A1.1 and A1.2. To do A1.1, you break it down into A1.1.1 and A1.1.2.

In even a small project, that means that your moment-to-moment work might be something like "do task A4.1.2.3.5.3.2.1.5.4". Not literally, but conceptually, that's what's happening. Every task involves a bunch of other tasks, which involve a bunch of smaller tasks, ad infinitum.

This is probably similar to your refueling of a nuclear aircraft carrier. Big tasks involve little tasks, which involve smaller tasks. I assume. I've never refueled a nuclear aircraft carrier. But I have developed a lot of software.

Every software project is a working a plan that has never been done before. Because when it is done, the result is software that is infinitely reproducible, so there is no need to do it again. It's as if somebody needed to figure out how to refuel a nuclear aircraft carrier once. And then after that, everybody who wanted to refuel just cut-and-pasted a fully-fueled carrier.

In many ways, writing software is like figuring out that plan. It's not following the plan, it's creating the plan. And somebody who knows how to do A can figure out that involves A1, A2, and A3. And they can probably figure out that A1 involves A1.1 and A1.2. But they can't predict all the way to A2.3.1.5.2.4.2.2.5.1.1.1.5.2. (It's been tried. It didn't go well. Google "Software Crisis.") Too many issues don't appear until you try to solve them for real.

And those little edge tasks way down at the bottom? They might take five minutes. Or they might turn into another nested set of tasks that takes five hours. Just today, I was working with a team trying to solve a simple problem: print the URL of their current web page. This was no problem. The tool we were using to serve web pages told us the current URL. But it only told us the url's path (the part after the domain name). We also needed the scheme ("https:") and the domain name ("news.ycombinator.com") and the port (":80").

And that wasn't something our tool expected us to want [1]. So a five minute task turned into a half-day marathon of reading documentation, trying things, and reading more documentation. It took us half the day to figure out how to do something that should have taken us five minutes, and we had assumed it would only take five minutes when we estimated the larger task two weeks ago.

Coders who know professional estimating techniques approach this problem by using Monte Carlo simulations that provide a probabilistic range of dates. The high-confidence numbers resulting from these simulations are usually way too far in the future to satisfy stakeholders, because the simulations have a long tail. (More can go wrong than can go right.) Professionals have found it's often easier to refuse to provide estimates than to fight over high-confidence estimates or educate stakeholders in interpreting probabilistic date ranges. Not estimating saves lots of time, too.

I hope this long-winded explanation is the help you were looking for.

[1] For the nitpickers in the audience, I'm obviously leaving out a huge amount of detail about how our REST API was actually interacting with its framework. But that's the gist--we were trying to find a clean way to translate our current absolute URL to another absolute URL. Even now, I'm sure we were missing something obvious.

[mdpopescu]

This is a much better explanation of the problem with estimates than my analogy :)

Especially this part:

Professionals have found it's often easier to refuse to provide estimates than to fight over high-confidence estimates or educate stakeholders in interpreting probabilistic date ranges. Not estimating saves lots of time, too.