Optimizer is not taking constraint in consideration.

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anon-user asked Apr 27, '23 Jeanette F commented May 6, '23

Optimizer is not taking constraint in consideration.

Hi Flexsim Team,

I am facing issues while adding constraints to the model. I want to get the best-optimized sequence but after adding colorsequence parameter as constant the optimizer is not working.

In the HCM_ColourChangePlanning table column no 63 and 64 have values 0,1 and the constraint is to take all 1 value first in the sequence. I have added this constraint value to performancemesure3 from parameter 15 and applied it in the Optquest but Otmizer results are not acceptable.

For this logic, I have written the code in the process flow attaching the image below.

Could you please help me with how can I make it work to optimizer?

Thanks and Regards,

Brijesh Kumar

Image Caption

Software Version:

FlexSim 22.2.4

optimize

· 4

anon-user commented · Apr 27, 2023 at 11:06 AM

@Jason Lightfoot

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Jason Lightfoot ♦ anon-user commented · Apr 27, 2023 at 02:43 PM

Have you tried using ==0 for the constraint instead of =0?

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anon-user Jason Lightfoot ♦ commented · Apr 28, 2023 at 05:12 AM

Yes, but still not working.

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Jeanette F ♦♦ commented · May 06, 2023 at 04:57 AM

Hi anonymous user, was Jordan Johnson's answer helpful? If so, please click the "Accept" button at the bottom of their answer. Or if you still have questions, add a comment and we'll continue the conversation.

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Answer 1 · 2023-05-01T19:42:50Z

Jordan Johnson answered May 1, '23

All parameters are constant unless you include them in the optimization. Only the parameters you check are allowed to be modified by the optimizer. The easiest way to set a constant is to set the parameter in the model before you run the optimization, and don't include it in the optimization.

Another approach would be to include the parameter in the optimization and write a constraint equation involving the parameter, not the performance measure

[MyParameter] <= 1

If you write a constraint equation using a performance measure, OptQuest has to simulate the solution and then determine if the solution violates constraints. If you write a constraint equation based on parameters, OptQuest can tell that the solution violates the constraint before running a simulation.

Also, you may notice that I used a <= operator and not an = operator. There is a note in FlexSim's user manual that for the version of OptQuest we use, constraints can only contain <= or >= comparisons, so an exact match comparison is not supported.

Here is the closest link:

https://docs.flexsim.com/en/23.1/GettingData/AdvancedDataGathering/RunningJobs/RunningJobs.html#opt

The note is in the section called Adding Constraints.

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