What if that turns out to be an inefficient (poorly-architected) way to break it down? But it's half-implemented by the time someone calls attention to it, and it doesn't get re-architected because it's too late now.

Breaking things down appropriately is, in my mind, 80% of the work. If you have your head straight, the implementation is easy; but it can take implementing virtually the entire thing to get your head straight.

> What if that turns out to be an inefficient (poorly-architected) way to break it down?

Don't break out later stages too early then! Just enough to get to MVP. That is the essence of agile and XP isn't it?

If I don't break them out "too early" then that often means I'm not breaking them out until I'm almost finished :)

> but it can take implementing virtually the entire thing to get your head straight.

Seems to fit your needs then!

Well, the developer didn't need it in the first place. It is not a useful tool for developers as we have better tools for developers. It is management that wants to see the work up in pretty JIRA lights and they want to see it before the project is already done.

That's how agile should be done. You should plan out the things that you are doing short-term in more detail and the things you are doing long-term in less detail because you don't know as much about it and it is more likely to change.

That sounds good but (as far as I know) Jira hard-codes the number of levels, so you quickly hit a point where you can’t break tasks down any further.

Presuming you are letting Jira decide there is a logical link, I suppose. You don't have to, do you? I must admit I haven't used it an awful lot, but maybe this is one of those traps that you use the functionality because it is there, even if it is not useful.

In this example you could for instance create 'Airport' as an task and just write on it that you are going to aim for a dirt strip first and are going to start a separate task for this.

This is the power and weakness of Trello, there is no link! Except of course you can create a new board called 'dirt-strip'

Well, I’d like the tool to display the levels in a useful way, sure. Even just nested bullet points would be okay.

The problem is many times you end up with tickets like 'create a runway' when there are already four perfectly good runways but the person doing the breakdown didn't realize that.

And if your developers don't have a bigger picture understanding then they also won't know that there are already runways they should be using.