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Vehicle stuck at sink


ToniG

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Hello all

I am relatively new to Simio and DES. I am trying to model a pallet conveyor.

It is a closed loop conveyor. I use the "vehicle" as the pallet that loops around the conveyor. At the source the part (default entity) is loaded on the pallet. At the sink the part is unloaded.

The problem that I am encountering is that the vehicles from time to time pile up at the sink, then after a certain amount of time they continue back to the starting point "Source1".

This happens more the more I increas the "initialnumber in system" of vehicles

The transfer-in Time for the sink is set at 0.

At the model trace I read this for the "Input@Sink1" : "the in Token waiting at VisitNode step for '1' other processes to complete."

I would apreciate any advice. Many thanks!

Vehicle_stuck_at_sink.spfx

Edited by ToniG
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Ok, I think that I sort it out.

I am not very confident of what I do but I think that it works now:

I changed the Vehivle "Routing Logic". Idle action: Go to home

image.png.af73dc59903ebb7c67f64d0706547662.png

AND

I changed for every server, secondary resources:

image.png.c4d6eec83ce6baf2aab9c01554c37c33.png

 

Earlier it did not work because the vehicle was stuck at the sink waiting for an entity to be available at the source. The idle action for the vehicle was to "Park at home"..

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  • 2 weeks later...

Happy new year!

One thing that I noticed is that with this model, the server never have a state of "blocked".

I increased the processing time of Server2 and added a status pie to Server1. The server 1 is either Processing or starved, but never blocked according to the pie. But it should be blocked part of the time since I increased the processing time of Server2 to force this.

It looks like the Server1 only accepts a new item to process if the path between Server1 and Server2 has room for at least one more vehicle. So the time that it should be blocked is considered as part of the "Starved" instead.

I tried to figure out why this happens without success. Anyone knows why this happens? I attach the model to the post. Thank you!

Input

image.thumb.png.a1f9cd5fa87095ab2f1e1d20d7334919.png

Server1 not blocked.spfx

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