[tboughen]

I’m a teacher without a tech background. My role is to schedule a high school timetable.

To do this I have been given software that is single threaded and will only run a single instance, so I have taught myself Hyper-V, and run several VMs with alternative searches simultaneously. These searches can take 12+ hours to run.

The software also runs 25% faster when allocated 2 threads maximum than when 3+ are available…

[jugg1es]

I have worked with senior software engineers that would never think to do this and do not have the skills to do it if they did. Impressive.

[xmonkee]

First of all, very impressive :) I AM a techie and I would never have come up with this solution, because I would have become obsessed with how the software knows it's running another instance and trying to hack that.

Second of all,

>These searches can take 12+ hours to run

WTF. What are these searches doing?

[tboughen]

Thank you!

The searches are trying to allocate groups of teachers to time slots, subject to the inputted constraints e.g. their students aren’t elsewhere, changing rooms are available if needed, a teacher hasn’t been allocated a different class already etc.

But I can’t tell the software which constraints are hard, which are soft, and which have alternatives we are indifferent about. Hence the need for parallel searches!

[neurostimulant]

This is basically traveling salesman type of problem called Constraint Programming. Plenty of library in this space if this interest you, like OR-Tools: https://developers.google.com/optimization

[_joel]

> >These searches can take 12+ hours to run

> WTF. What are these searches doing?

This is why you're a techie ;)

[noir_lord]

For a non-techie to pull that off is honestly impressive.

Kudos.

[_joel]

Love these solutions to a problem, well done :)

[mercurialuser]

If the software is FEL, an open source time-tabling software, you can run the gui-less executable. I did it in Linux on a 30× core server, starting 30+ processes.

Edit: read the other answers. In FEL you can specify hard and soft constraints. Search can be long nonetheless...