OptaPlanner VS or-tools

However, if you need to solve constraints etc., see: https://www.optaplanner.org/

Try looking for something built around Optaplanner - basically taking the end game of rostering and working backwards.

OptaPlanner takes some of the items tracked in tool like Odoo and creates plans based on them. I.E. how do you manage shifts while juggling multiple constraints (Jerry can only work weekends, Jeff can only work afternoons, Jim can work weekends but only on double time, etc.)

There is a library out there called Optaplanner that is designed for optimization of NP complete problems. It is hard to tell if that is exactly what this is, but I think you should be able to use this regardless.

Just stumbled upon https://www.optaplanner.org. Looks very interesting but also really overkill.

OptaPlanner - a generic scheduler.

OptaPlanner

I've never used it but it sounds like OptaPlanner may be a scheduler in the same vein?

Having joined may father and his friend during the process of cutting down big trees in the village neighborhood I can personally vouch that this indeed a cumbersome and very complex task for both the planning and the execution phases. However, for us the tasks are made easier by the trimming of the tree's branches since my father's his friend is the expert tree climber.

From your descriptions, it seems that your tree cutting procedures do not involved precut of the tree's branches before cutting the tree down.

I've got the feeling that this cutting tree problem can be solved by constraint programming techniques [1],[2]. Alternatively generic tools for constraint programming, for example OR-Tools and MiniZinc can probably do the same if not better [3],[4].

[1] Logic, Optimization, and Constraint Programming: A Fruitful Collaboration - John Hooker - CMU (2023) [video]:

https://www.youtube.com/live/TknN8fCQvRk

[2] "We Really Don't Know How to Compute!" - Gerald Sussman - MIT (2011) [video]:

https://youtube.com/watch?v=HB5TrK7A4pI

[3] Google OR-Tools:

https://developers.google.com/optimization

[4] MiniZinc:

https://www.minizinc.org/

Yep - i thought / hoped / assumed it was about Optimizers aka Sat solvers, etc

A la https://github.com/google/or-tools

https://developers.google.com/optimization

https://github.com/google/or-tools

Small NP-hard problems aren't actually that bad. You can usually formulate them as eg a integer programming problem or a SMT problem, and throw an off-the-shelf solver at them.

You only need to learn the solver once, and you can re-use it for all kinds of problems. (Assuming that your instances don't have to be solved with low latency. Eg only as part of your level generation process, or at most when loading a randomly generated level, but not every frame or so.)

https://developers.google.com/optimization has a decent collection of tools.

Just saw that it looks like an upcoming release of OR-Tools might include reified tables: https://github.com/google/or-tools/commit/94f3d9b46870e7ea04...

Google OR - Tried to represent a solution to be a 5 dimensional matrix with an hour granularity. Dimensions are stations, program, project manager, day and time. If matrix[station][program][project manager][day][time] = 1, then that set is assigned, otherwise not. The main issue encountered here is about time slots, as they are not necessarily on a per hour basis. We tried time slots to be in a 5-minute interval. However, constructing the constraints that would adhere to each programs duration was proven to be difficult.

If you are just interested in getting a solution or for having a reference solver: There is a sudoku example in the OR-Tools package that uses constraint programming.