Send Operator to the longest queue and assign it there till queue is empty

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Korbinian H asked Jul 5, '17 Korbinian H commented Aug 2, '17

Send Operator to the longest queue and assign it there till queue is empty

Hello guys,

How can I implement a rule to check for the longest queue, then send the operator there and transport and process the items, until the queue is empty?
After this, the operator should be again assigned to next longest queue.

I have attached a model where workers already carry the items and process them afterwards. I have implemented this behaviour like in the Task Sequence Tutorial 2, but the operators still get randomly assigned.

Thanks in advance.

longestqueue.fsm

Software Version:

FlexSim 17.1.2

task sequence queue content operator assignment

longestqueue.fsm (19.9 KiB)

Answer 1 · 2017-07-05T21:50:50Z

Steven Hamoen answered Jul 5, '17 Korbinian H commented Jul 22, '17

@Korbinian H I would use process flow for this. Your operators are the tokens and the items are on a list. If your operator looks for items from the same queue. If it can't find one anymore he takes the queue with the highest number, not used by the other operator.

· 3

Korbinian H commented · Jul 21, 2017 at 11:31 AM

Thank you for your answer!
As i have never used process flow before, I am not able to fully implement your logic. I am not able, to develop a loop to assign an operator until the queue is empty, and release him afterwards to pick a new queue, which is not used by another operator.
I was able to filter the list, so the operator picks items from the longest queue, but i dont know how to compare the length of queues and how to assign the operator to a queue, especially if new items arrive. It would be a great help to me if you could adjust my model.
It already contains a process flow, but without a working loop to check, if there are still items in the queue.
Thanks for your help :) help2.fsm

0 ·

help2.fsm (29.3 KiB)

Steven Hamoen Korbinian H commented · Jul 21, 2017 at 03:16 PM

@Korbinian H

Here is your model back with some changes. I hope this is what you would had intended?longest-queue.fsm

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longest-queue.fsm (30.0 KiB)

Korbinian H Steven Hamoen commented · Jul 22, 2017 at 08:42 PM

Thank you for your quick reply!
Almost, but after a while (~110 time units) the operators start to unload from the same queue. It looks to me, as if something in the query in the "Pull from List" activity is not working properly.
As I am not to familiar with coding, could you please help me one more time? :D

Furthermore if I change something in the query, the changes just won't be applied, only if i save the model, close and open it again. Might this be a bug of Flexsim?

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Answer 2 · 2017-07-21T13:28:43Z

Anna Lisa Dierking answered Jul 21, '17 Korbinian H commented Aug 2, '17

@Korbinian H

I have an example for you that worked for me without using Process Flow.

I have 2 global variables (arrays), one containing all the processors and one all the operators. Every processor also has a label containing the operator it is associated with ("Operator") [label is empty onReset] and every operator has a label with the processor he is associated with ("Maschine") [label is empty onReset].

Most of the logic used is inside the processors. I used the onEntry trigger to figure out if there is an operator that is supposed to work that machine. If there is no operator associated the processor looks through the array to see if there is any operator available (= label "Maschine" on operator is empty). If there is a free operator, the label "Operator" on the processor refers to the centerobject-port-number that connects that free operator to the processor.

After the last item leaves the processor, the processor sets the operator free (-> label "Operator" on processor and label "Maschine" on operator are empty). The Processor also sends a message to all the other processors to let them know that they can now look for a free operator if there is no operator already associated with the processor.

I hope this is helpful.

beispielmodell-ald-f1714-rev01-12.fsm

beispielmodell-ald-f1714-rev01-12.fsm (31.6 KiB)

· 1

Korbinian H commented · Aug 02, 2017 at 02:21 PM

@Anna Lisa Dierking Thank you for your model.
I have tried to implement this logic in my existing model. After a while, errors occur, as the processors are not able to pull from the queue anymore. Also I am not able to find a method, how to assign an operator to the longest queue. Do you have an idea, how to solve this issues? Thanks in advance :) 0802-processor.fsm

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0802-processor.fsm (33.0 KiB)

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