3 ms·

Nothing new, nothing to learn here. Pure pr. Aka give me one OR guy and a gurobi license and we will beat their result. Bonus at the end of the excercise you

Nothing new, nothing to learn here. Pure pr. Aka give me one OR guy and a gurobi license and we will beat their result. Bonus at the end of the excercise you will have an or guy that can help you solve other use cases as well.

dog0000 2y ago
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 http://vrp.galgos.inf.puc-rio.br/index.php/en/updates - where's Google?
- dvaun 2y ago
  How does one end up in this space of work?
  - whatever1 2y ago
    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)
bubblyworld 2y ago
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 2y ago
  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 2y ago
    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 2y ago
      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 2y ago
        Okay, well, thanks for your thoughts.
      - chaoxu 2y ago
        > 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 2y ago
    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 2y ago
    A heuristic using problem specific structure can beat Gurobi which is for solving general mip.
- cerved 2y ago
  they do have a Gurobi license

dog0000 2y ago

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

dvaun 2y ago
How does one end up in this space of work?
- whatever1 2y ago
  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)

bubblyworld 2y ago

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 2y ago
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 2y ago
  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 2y ago
    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 2y ago
      Okay, well, thanks for your thoughts.
    - chaoxu 2y ago
      > 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 2y ago
  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 2y ago
  A heuristic using problem specific structure can beat Gurobi which is for solving general mip.
cerved 2y ago
they do have a Gurobi license