https://apenwarr.ca/log/20171213 (on HN: https://news.ycombinator.com/item?id=15912929)
Of interest, the author mentions Work Breakdown Structures. A WBS is meant to obey the "100% rule": it must contain all the work (ie, sums to no less than 100%) that goes into a project and it include only the work that goes into a project (ie, sums to no more than 100%). So if something shows up that wasn't foreseen, you add it immediately and adjust the fractions.
So far, this is not helping the competing-work problem. That's where old-school project management adds control accounts. Each item in a WBS has an account where individuals "spend" their hours, dollars and so forth. If you have competing work, then the dollars and hours get spent on a control account belonging to some other WBS.
Finally, this typically gets rolled up into an "Earned Value" plot. You can show much time and money was intended to have been spent at a given point in time and how much has actually been spent. If you notice that the rate of spend is below intended, you go looking for where the leakage is. Since you can perform Earned Value analysis on any part of the graph of control accounts, you can quickly identify what's going on.
And that's when two project managers begin to yell at each other.
This kind of apparatus comes with a lot of overhead. But I think it's underutilised, even informally.
I did see a 5 month, 5 person, fixed cost contract take 18 months, 10 persons, and sank the company.
Never, ever, try to estimate software projects.
So...just go around telling people you need an indefinite amount of time to do anything at all?
Of course, they ignore the fact that the requirements changed during the project every single time.
That said, every project I've ever worked on was "new ground" and had never been done before. Musk can estimate how long it will take to make the next Tesla but might have a bit of trouble estimating the opening of the first Mars colony.
There was a posting about estimating that talked about walking in California. It was perfect. Can't find it again though.
We estimate all the time.
So the assumption of bringing n people to work on a projects increasing the productivity n-fold doesn't seem totally absurd when they are working on the project from the beginning. It might not be exactly n but (n-m) due to increased management, communication etc. So we might discuss how big is m? Still there should be some increase in productivity because that's essentially how huge projects work.
