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Ricardo B3 avatar image
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Ricardo B3 asked Ricardo B3 commented

How can I make two forklifts move items from the same queue?

I'm very new to flex sim, I'm simulating an unloading scenario for a warehouse, where three forklifts and a conveyor unload a truck, the first forklift unloads the truck and puts the items on the first queue, the second forklift takes the items from the first queue to the conveyor, the conveyor takes the items to a second queue, the third forklifts take the items from the second queue to a third one, what I still can't program is that when the first two forklift totally finish unloading the truck, I want the second forklift to go and help the third forklift move items from queue 2 to the third one. I know that I need to give priority to second queue so only when it done the second forklift goes to help the third one, but I can't make a queue use both center ports.

FlexSim 7.7.4
task executerqueue contentcenter ports
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Joerg Vogel avatar image Joerg Vogel commented ·

That is job of the dispatcher. You connect the queue with the dispatcher by an center connection and the dispatcher is connected to the forklifts by an object connection (a-type). The dispatche is responsible to store the tasksequences and to transfere them to an available taskexecuter.

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Jeff Nordgren avatar image Jeff Nordgren commented ·
@Ricardo B3

Are you able to attach your model or a sample model so that we can see exactly what is happening in the model? That would help us be able to give you a more specific answer to your question.

Thanks.

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Phil BoBo avatar image
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Phil BoBo answered Ricardo B3 commented

Here's a sample model (forklifts.fsm) that shows how you can do this with the standard 3D objects.

As Jörg said, you can use a dispatcher to send the task sequences from the second queue to multiple forklifts.

You can use the priority and preempt values on the first queue to make the tasks from that queue higher than the tasks from the second queue.

If you want finer control over exactly what is happening, then you should use Process Flow as Jordan suggested.


forklifts.gif (11.3 MiB)
forklifts.fsm (38.5 KiB)
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Ricardo B3 avatar image Ricardo B3 commented ·

Thank you very much, your answers were very useful, I'm now able to accomplish my simulation.

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Jordan Johnson avatar image
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Jordan Johnson answered

Give this answer a look:

https://answers.flexsim.com/questions/45647/how-to-use-more-than-one-operator-to-carry-out-sam.html

It demonstrates how to create a set of tasks, and to have a Task Executor check multiple task lists.

What you need is a flow where the second forklift checks to see if there is work to do at the truck. If there is, it should do that work. If there isn't, it should check for work at the Queue. In the answer above, each task executer looks for someone who needs help (highest priority) and then tries to do their own job. You could adapt that approach to your situation.

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