I have a niggling feeling somewhere that JSON is the wrong language for this. Something like cue lang may be the right thing. (https://www.sobyte.net/post/2022-04/cue/)
The nice thing about scoring with SA is that I don't need to think like an operations research student. I just think in code with if/then/else and the number of dimensions don't matter. The code is working fine for now but now the problem is a business requirement to make it MUCH more complex and factor in a whole new set of constraints. SA will straight up not work with it because the scoring itself can take tens of seconds now. So I need to come up with a new 'proper' way, hence my renewed interest in solvers.
pretty sure there's heuristics at play...but how would you do it ? take your own example of
>constraint of 100hrs/week/machine but also 168hrs/week/room full of specific machines. In other words, while each machine can run 100hrs/week, if there are 4 of them in the same room, only one can run at a time, and so combined machines in a given room cannot be over 168hrs/week
From my experience, the most important thing to get right in any local search algorithm is the state representation and the moves generated. If those work well, then any combination of metheuristics like simulated annealing, tabu search, population based search, restarts, parallel exploration, portfolio methods, and so on. Quite often the literature focuses only on the meta heuristic, but not so much on the representation, which IMHO can be an issue.
As an example, for some problems that I have solved with local search, the most impact in improving performance of the algorithms have been in improving the base. Making moves and score updates fast, and making the moves generated meaningful in the context.