I'm not saying agile has no place, just that many projects would benefit from a little bit more foresight.
Also, I think successful agile projects are often those where the long term planning is there, even if it is not obvious or talked about a lot.
There is really a spectrum of choices for how much you plan and tradeoffs with each level.
Success is finding the right balance for you, your team, and your product.
"If the physical properties of concrete changed every 6 months, then structural engineering practices would look very different."
But that's the world most software is developed and lives in.
"Well, last week it was driving a bus."
Waterfall in software was continuously changing those fundamental parts. You'd be fine tuning the irrigation and needed to destruct the whole bridge because some new requirements came up. That's where the anti-Gantt and "bad waterfall" comes from, the reality is the software world as a whole moves way quicker and requirements are way more malleable, subjective than building a bridge.
Exactly this same thing also happens in non-software "waterfall" projects as well. Mid-project fundamental requirements changes which result in having to re-engineer large parts of the project. This is one of the reasons military acquisitions are so expensive, there's a huge problem with requirements changes.
People keep repeating that, without any empirical evidence at all. If it were only software developers justifying a body of knowledge, it would be ok, but all kinds of people keep repeating that.
Yet, that kind of planning predictably fails every single time in every single engineering practice.
I can guarantee you, if an engineer designs the structure of a bridge, send it to a crew to construct, and go away to only test after it's done, the bridge will fall down before it's even built.
Passing a design down and going away doesn't work. Scheduling tasks before you star them doesn't work. Testing only at the end doesn't work.
The one thing civil engineering has that resembles PMBoK is designing things beforehand. And only civil engineering does that, only because they can't prototype.
Hum... Have you used them that way? And have you needed a project design to actually discover risks and estimate that you need to act on them?
Or better, have you found any unexpected risk on a project design, and seen it materialize on practice?
> If something slips you know how to update your estimates for everything downstream.
And then your renewed estimates will be wrong again. No idea if more or less wrong than before your revision though. It can go either way.
Yes. These things are all over the place in defense.
One of the most important exercises in doing a Gantt chart is finding the "critical path" which is the set of tasks which can't slip without effecting the final timeline. If step two has two separate tasks that step 3 depends on, the longer task is on the critical path, the shorter is not because the shorter task can be delayed at least some without affecting when step 3 starts.
As the project continues you update the chart with what actually happened vs. your plans. The goal is to minimize changes, sometimes you can, sometimes you can't, but when there are changes you can see how the whole flow is affected and you can easily communicate the change in deadlines, changes in budgets, you can pull people off of one task and put them on another, etc.
In agile you do way less of this planning and the path is usually much more simple so you don't _need_ these tools to be successful.
Not all that long ago, software was distributed on physical media such as floppy discs and CD-ROMS.
This kind of planning is _necessary_ for traditional engineering projects where certain steps of the process can take months or years and requires scheduling of many resources.
Purely software projects usually don't need that because if your tools are good you can ship a completely new version in minutes to hours instead of months to years. You also get very easy do-overs if there are mistakes which you don't get if you're building a bridge or a factory.