I am having trouble with my Problem Instances, which seem to be not "complicated" enough.. Is there a way to find out what the problem is? It is being solved in a matter of seconds even if the problem instance contains over 100 of periods...Although The solution seems reasonable

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I attach the .gms and the instance .inc files and the model description: https://seafile.rlp.net/d/a8d1fa91f43d429fa7f0/

  • $\begingroup$ This might not be the question of the century, but why the downvotes, without even the courtesy of saying why they were given? Are the downvoters upset that the OP didn't enter everything in MathJax? Give me a break. $\endgroup$ Dec 6 '20 at 21:13
  • $\begingroup$ @MarkL.Stone Thank you. I was hoping someone could interpret the solve state of my .gms because it looked like a lot of presolve reduction was going on... $\endgroup$
    – Eddiee
    Dec 6 '20 at 23:18
  • 2
    $\begingroup$ @DerEddie in principle there's nothing suspicious whatsoever about a large problem being solved very quickly - it could simply mean that there was a lot of special structure present that was exploited. $\endgroup$ Dec 7 '20 at 15:19

For a test problem, check manually (outside GAMS) that the solution satisfies all constraints. If not, your GAMS model may be wrong. If all constraints are satisfied, try using a different solver and see if the same objective value is achieved. If the other solver gets a better result, your current runs may be stopping short of optimality. If the objective values match, your problem is apparently easy (which is a good thing in the real world, perhaps not such a good thing in portions of academe).


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