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Aidan W avatar image
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Aidan W asked Aidan W commented

Sub Flows not utilizing operators

Hello,

In my current model my operators are not being used at the stations despite the Sub Flows acquiring a resource and the stations calling for the use of an operator during processing time. They are collecting the material and moving it as intended but won't operate on it. What did I do wrong?

temp.fsm

FlexSim 21.1.2
operatorsflexsim 21.1.2subflowsub flowprocessing
temp.fsm (2.3 MiB)
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Joerg Vogel avatar image Joerg Vogel commented ·

Have you tried to do it options of processor properties in your 3D model? Each Processor can call an operator or an operator team to assists for setup and processing. If you preempt such an operator from a processor then the processor goes into a stop and is waiting for the return of an operator. You can try to replicate the mechanism in process flow, but the mechanism has been existing in FlexSim a long time before Process Flow has been introduced into FlexSim logic handling.

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1 Answer

Jeanette F avatar image
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Jeanette F answered Aidan W commented

Hello @Aidan W,

There were a few things you had set up incorrectly. For one the operators need one connection to the dispatcher that goes from the dispatcher to the operators. Next, your sub-flows do not need to acquire an operator. That has already happened by selecting use operator in the Queues' output. Next, your subflow controls an operator till the box has been processed and moved to its next queue, so you do not need to have the processors connected to the dispatcher and you do not need to select use operator.

I believe that was all I changed but here is your model for you to reference. SubFlow_JF.fsm


subflow-jf.fsm (281.1 KiB)
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Aidan W avatar image Aidan W commented ·

One underlying issue with this version of the model is how the operator breaks and shift changeovers are handled and the effect on the processors. In each shifts' time table there are 3 different breaks that are meant to pause the processing at the station when they occur. An easy solution would be to set those breaktimes to a table specific to each of the processors to mimic those breaks. What isn't so easy to fix is when shift changeovers occur, the processors continue to work the material even though no operators are present, and due to how the subflow is formatted, they continue doing new work instead of moving the finished leading to stations getting backed up. Over time this clogs every station and new work can't be accomplished.

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Eric M avatar image Eric M Aidan W commented ·

I think I figured out a way to solve this problem. I got rid of the resource activities like Jeanette had noticed. I kept the dispatchers connected both ways and used the "multiple teams" setting for the operator on the processors with a priority of 1. This setting makes it so the dispatcher can reassign tasks to new operators which means the shift change will work well.

I then added a Finish TS and Create TS before and after the Wait for Event activity so the dispatcher could have access to the operators during the processing time (the priority set to 1 means that the operators won't go pick up another box until the item is processed). I set the priority on the new Create TS to 1 as well. This makes sure the operators will always finish the whole sub flow before going to pick up another box.

temp-em.fsm

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temp-em.fsm (283.1 KiB)
Aidan W avatar image Aidan W Eric M commented ·

Works perfectly!

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