Yuck. I think the agile approach might be better here. It's better to expose your plan to reality ASAP and adapt along the way.
Except, that's not how agile really works. How agile works is "bosses" have an hour planning meeting, and then act as though they have a veeeeery robust plan (like you talk about) and get upset if things do go according to their quick one-hour plan. So much for adapting along the way.
And anyone wonders why we're in this situation? We dug this hole, kids. (And to be clear, I'm guilty. I'm not trying to be better than anyone. I am not! I'm just attempting to explain it.)
With agile, building houses still somewhat works because people will do that planning in their heads. So, knowledge will end up _only_ in people’s heads, not even in everyone’s heads, and will deteriorate there, even if those people do not leave the project.
So, by the time it’s time to do a large-scale update to the house (add a room, update ventilation to modern standards), nobody knows where the ventilation ducts run, why one of them is so much larger, that there’s asbestos in the ceiling, etc.
And of course, some people try to use agile not for building houses, but for building apartment blocks.
It was a way to bring some sense of order to what was chaos: new requests coming in all the time, work being dropped partway through to deal with the new requests, little progress on any front.
I think agile works really well in this kind of context by bringing in a sense of discipline and keeping new work at bay until the beginning of the next cycle[1]. It can also help to keep teams delivery focussed in other contexts but, key point, does not obviate the need for additional planning outside the sprint/iteration framework.
The problem really occurs when people treat agile as sufficient on its own, or as the one project management tool to rule them all. Total nightmare, especially with multiple teams involved.
[1] How workable this is in practice is open to question: I can tell you it's not always a great approach in an environment where client projects typically last a few days and on time delivery has been known to depend on a critical bug fix for a legacy codebase. Especially problematic when requests come in either during the launch phase, because there's usually a fairly hard window, or during the reporting phase, because there's a delivery deadline looming.
You ain’t wrong about how most businesses implement “agile,” though. :)
Learning and applying "how to plan a project" has pretty universal career relevance. I suggest 30-40 hours of study time, and it's around ~$600 to buy the book, take the exam, etc.
Why do we, as an industry, expect to be able to run a project to schedule when we often give it the most cursory of glances in the planning stage? I work for a very large integrator and we don’t plan at all. We jump in and start while we’re ‘planning’. It’s absurd.
He and I have long said that if the people who built [hospitals|bridges|aeroplanes] behaved the way we did, the world would look very different [1]. Now, thanks to my recent PMP-by-proxy, I’m starting to understand.
[0]: Project Management Professional. One of the main accreditations for project managers, I think PRINCE2 is the other one.
[1]: I’ve seen the project schedule for a railway line extension. “You really plan a concrete truck coming three weeks from now down to the half-hour?”, I asked my friend. She does.