People can hide the fact that they have a big ball of mud fir a very long time, and they only want to talk about improvement after hunts have gotten miserable.
4-11 years depending on exactly what you'd define as "brownfield"
> People can hide the fact that they have a big ball of mud fir a very long time, and they only want to talk about improvement after hunts have gotten miserable.
True but beside the point. The same point stands: you can always find a way to make a worthwhile improvement in two weeks - something that's useful on its own, even if it's also the first step of a much bigger improvement plan.
Sure, sounds straightforward enough. Start with simple cases (e.g. universe is a unit circle), you can definitely implement useful pieces within two weeks.
> first the mathematical models behind it need to be created then implemented in software.
That's not a real (i.e. user-facing) requirement.
In my experience everything can be broken down if you spend five minutes actually trying to break it down. And the benefits are very much worthwhile.