Traversal Points accumulating infinitely

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Marcello Rosadini asked Jun 11, '24 Jeanette F commented Jun 21, '24

Traversal Points accumulating infinitely

We are working on a simple system that includes a simple sorting conveyor loop. The model is quite simple, but after 1 hr of simulation it starts to get really slow and it seems like the reason is that the registry of traversalPoints keeps growing infinitely every time that an item reenters the loop. I have made a small sample to show the issue.

Is this expected behaviour?

Is there a way to reset or clear this data ?

I have tested in older versions of FlexSim (23.0) and the behaviour is the same.

conveyor loop.fsm

Software Version:

FlexSim 24.1.0

conveyor traversal point

1718116706466.png (2.8 MiB)

conveyor-loop.fsm (39.3 KiB)

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5 |100000

Attachments: Up to 12 attachments (including images) can be used with a maximum of 23.8 MiB each and 47.7 MiB total.

Lambert commented · Jun 14 at 05:43 AM

I am also having this issue, it makes it unfeasible to run experimenter or optimizer.

any help?

thank you

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Jeanette F ♦♦ commented · Jun 21 at 06:44 PM

Hi @Marcello Rosadini, 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.

If we haven't heard back from you within 3 business days we'll auto-accept an answer, but you can always comment back to reopen your question.

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Answer 1 · 2024-06-14T17:51:02Z

Jordan Johnson answered Jun 14, '24 Lambert commented Jun 15, '24

I did a bit of investigation about this. I think the long list of traversal points has to do with blocking the input source. Here's an example model:

conveyor-loop-2.fsm

If the source places six items on the conveyor, the model runs quickly, and the traversal points list does not grow. If you change (in the source's arrival table) the number of items to 7, the number of items on the conveyor stays the same, but the model gets slow.

My theory is that when an item is attempting to get into the loop, but there is no room, the logic changes a bit. I think each item is trying to determine when it would be clear of the entry transfer or something like that.

As another test, I created another model with a loop, but in this model, I use a control area. The basic idea is to only put the item on the loop if it wouldn't be blocked. It's a bit of a pain, but it might help you work around this issue. By doing this, it seems to avoid the issue and the model runs quickly:

conveyor-loop-fixed.fsm

I'll add this to the dev list to investigate.

conveyor-loop-2.fsm (37.9 KiB)

conveyor-loop-fixed.fsm (49.4 KiB)

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Attachments: Up to 12 attachments (including images) can be used with a maximum of 23.8 MiB each and 47.7 MiB total.

Lambert commented · Jun 15 at 04:50 PM

thank you.

hopefully it'll get fixed in future patches.

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