Gap Optimizing Process Flow giving inconsistant gaps

[evan_m]

[ FlexSim 19.2.3 ]

gap-optimizer-not-working.fsm

I'm trying to use a merge controller with the gap optimizing process flow included with FlexSim, but it keeps releasing slugs too soon. If you run the attached file you will see but the gaps range from being 0.1" too small to being half the requested size. How do I correct this?

If the solution requires editing the code, please be thorough, I have limited coding knowledge.

[evan_m]

I know it isn't set right in the uploaded file. but changing the release strategy to 0 like you're supposed to doesn't change anything.

[tanner_p]

Hi @Evan M,
I apologize that it's taken a long time to get back to you on this post. I've looked at this model a number of times and I'm not sure what's causing the conveyors to release early. I've tried looking at the PF code, I've altered the speeds and distances of conveyors, and I even built a similar model and I just can't figure out what's wrong. I'm wondering if it's something missing from the Gap-Optimizing PF. Something like a wait for event or label that's not assigned.

Just out of curiousity, what happens when you use the merge controller without the gap optimizing process flow?

[evan_m]

No worries.

When you remove the gap optimizing flow, it releases one at a time, so only one slug can be on the merge conveyor at a time.

[anthony_johnsonT83CM · Accepted solution]

It looks like the problem is caused because conveyor transfer settings for TransferType1 were changed. The "Use Speed of" setting was changed to "Sending Conveyor" instead of the default "Receiving Conveyor." Unfortunately I did not take this setting into account when I implemented the gap optimizing process flow. I assumed this setting would be the default. It apparently expects the transfer setting to be "Receiving Conveyor" such that if it is not set to that setting, the math for time estimation gets off. Items speed up later than they are supposed to, and thus the resulting gap is smaller than it should be.

If you change it back to the default this fixes the issue. I'll put an item on our dev list to try and make this more robust.

Also, you should delete all of the default code for the merge controller's release strategy, in the merge controller's properties window. Right now it's doing round robin if available, which messes with the process flow's merge logic (at least on the first slug release).