Nothing new, nothing to learn here. Pure pr. Aka give me one OR guy and a gurobi...

bubblyworld · 2024-06-06T06:36:49 1717655809

From an outsider... why does it seem that easy to you? They had a team of OR people working on this and presumably the money to buy a gurobi license.

whatever1 · 2024-06-06T09:15:53 1717665353

Because they did not show they used any methodological approach that we don't know for the past 30 years.

And according to the PR they did not use gurobi (or any sota mip solver), just their in-house lp solver in combination with shortest path algorithms and the fix-and-optimize heuristic.

Likely your particular use case will not fit their model anyway (for example you may want to consider contracts of affreighent along with leasing entire vessels).

So yes, or scientist and gurobi will definitely win.

bubblyworld · 2024-06-06T09:25:42 1717665942

On the other hand they cleared an open source benchmark by a long way, for which people have had plenty of time to apply existing approaches, right?

This is just a PR article, it's hard to say what they did or didn't try before arriving at this solution.

whatever1 · 2024-06-06T09:32:02 1717666322

Because frankly nobody gives a sh about throwing resources and finding just better (not globally optimal) solutions to synthetic benchmarks.

Academics care about proving optimality. Businesses care about their own specific use case and not synthetic benchmarks.

bubblyworld · 2024-06-06T10:26:54 1717669614

Okay, well, thanks for your thoughts.

chaoxu · 2024-06-06T17:20:58 1717694458

> Because frankly nobody gives a sh about throwing resources and finding just better (not globally optimal) solutions to synthetic benchmarks.

This does not align with my experience of people working in OR.

cerved · 2024-06-06T09:27:48 1717666068

How do you come to this conclusion? They way I read it rather sounds like they use the CP-SAT solver with LNS and LS workers, parallelized over multiple machines

chaoxu · 2024-06-06T17:16:47 1717694207

A heuristic using problem specific structure can beat Gurobi which is for solving general mip.

cerved · 2024-06-06T12:17:42 1717676262

they do have a Gurobi license

dog0000 · 2024-06-06T02:36:54 1717641414

Strong agree. I did a bunch of work on capacitated vehicle routing problems - basically the same as this +/- some bespoke constraints for shipping context maybe.

I benchmarked OR-Tools extensively vs e.g. LKH3 + my own hand-written solvers ... it's not a remotely credible library for these things, last time I checked. So ... don't have a lot of faith in Google's offerings here.

http://vrp.galgos.inf.puc-rio.br/index.php/en/updates - where's Google?

dvaun · 2024-06-06T03:09:28 1717643368

How does one end up in this space of work?

whatever1 · 2024-06-06T09:20:50 1717665650

Operations research related studies and work for a logistics company or a company that does some logistics itself (e.g. oil and gas, airlines etc)