
Comparison of Metaheuristics [pdf] - mindcrime
http://www2.cscamm.umd.edu/publications/BookChapter_CS-09-13.pdf
======
aqsalose
Quickly scanning the paper I did not find any actual comparison of
metaheuristics and their behaviour, sans the table 1 which lists their
possible parameters.

It's all well and good to list sensible sounding principles "for meaningful
comparison of metaheuristics", but I was kind of expecting to see those fine
principles applied in meaningful examples.

~~~
shoo
yes, from a skim read, there didn't seem to be a lot of meat here.

lots of the "popular metaheuristics" as described won't be anything
approaching state of the art, and i doubt their test bed considers problem
instances that are hard or of industrial relevance. so the paper sort of seems
to be about a method to compare the performance of uninteresting algorithms on
uninteresting problems, without doing any comparison.

tangentially, in contrast, here's something from a vendor of commercial
discrete optimisation software (from 2016):

> Pasco Shikishima, a Japanese leading food company (¥165 billion,
> equivalently $1.6 billion, in annual revenue), has chosen LocalSolver to
> solve what is probably the largest real-life optimization problem in the
> world.

> MIP solvers needed the original problem to be decomposed into almost twenty
> subproblems, each one solved separately, then leading to a poor global
> solution

> Pasco's supply chain involves 15 factories in Japan, each one with several
> production lines, and more than 100 distribution centers. Pasco's catalog
> contains more than 1,000 products. 900,000 orders have to be executed each
> day in Pasco's factories. For each order, Pasco has to decide where and when
> to produce it. Moreover, Pasco has to decide where to source raw materials
> and which routes to deliver distribution centers. The goal is to minimize
> production and distribution costs over several days of horizon, while
> respecting production and distribution capacities. Here is the scale of a
> LocalSolver instance solved by Pasco to plan the next 3 days: 32,670,717
> expressions (that is, intermediate variables) including 8,307,431 binary
> decisions, 991,251 constraints, 16 lexicographic-ordered objectives. This
> model was solved in 3 minutes of running time on a modern but standard
> server, including input and output processing times.

[https://www.localsolver.com/news.html?id=70](https://www.localsolver.com/news.html?id=70)

this probably would have been a pretty fun project to work on, given that
there was already an incumbent optimisation system in production, so a lot of
the required prep-work and IT infrastructure for being able to gather and
clean the input data for planning would have been in place. a sub-percentage
improvement in optimality of the solution at this scale might translate into
tens of millions of dollars of net profit for the company.

~~~
IanCal
Very interesting. Is there any hint as to how much LocalSolver costs? If
they're doing 3 minute runs for major optimisation jobs for massive companies
on a single server, I imagine the "contact us for pricing" should give me a
hint that it's quite a lot.

~~~
shoo
From memory I believe their competition (gurobi etc) would charge somewhere in
the range of $10k-$100k per year for a server, perhaps toward the upper end of
the scale if the server is used to solve problems for a number of clients. I
haven't paid attention to pricing for this for a few years.

~~~
IanCal
Thanks, this is the first I've seen of the commercial side of solvers so very
useful to have that kind of order of magnitude idea.

------
palad1n
Does anyone use genetic algorithms still?

~~~
nerdponx
Yes. E.g.
[http://epistasislab.github.io/tpot/](http://epistasislab.github.io/tpot/)

