How to let ASRS determine whether to put in or take out based on duetime

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Rykou asked Apr 4, '24 Rykou commented Apr 5, '24

How to let ASRS determine whether to put in or take out based on duetime

Hi everyone,I'm trying simulate a Automatic Storage Retrieval System.In my current model, there are three items need to be moved to Rack and two items are already on the Rack.

I'm confused about how to make ASRS choose items to move based on duetime, and duetime decreases with runtime, the logical priority of transportation is as follows:

1. As long as there are items in Queue, it will be moved to the Rack first.

2.The smaller the duetime on the shelf, the higher the priority it will be transported to Sink.

The attachments are as follows.Thanks.

ASRS determine duetime question.fsm

Software Version:

FlexSim 24.0.1

asrs logic duetime

asrs-determine-duetime-question.fsm (39.6 KiB)

Answer 1 · 2024-04-05T08:18:23Z

Felix Möhlmann answered Apr 5, '24 Rykou commented Apr 5, '24

You could customize the Queue Strategy to work based on the difference between current model time and duetime.

You've already given the queue priority by allowing its tasks to preempt others. The other tasks shouldn't be aborted though, or the items in the rack at that time would never be moved.

asrs-determine-duetime-question_1.fsm

capture1.png (27.8 KiB)

asrs-determine-duetime-question-1.fsm (39.7 KiB)

· 4

Rykou commented · Apr 05 at 12:16 PM

Hi @Felix Möhlmann, thanks for your reply.

I have executed the simulation.But I found that the simulation is a little different with what I expected. During the simulation, when two items arrive at Queue at the same time, ASRS will only move one of the items from Queue to Rack then moved other items from Rack to Sink.But I expect to place both items from Queue to Rack one by one then moved other items from Rack to Sink.It means that if items arrived in Queue, ASRS will send the item from Queue to the Rack immidiately then do other action.

And I found that the priority of moving items from Rack to Sink isn't based on the smaller item.dueday value.

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Rykou commented · Apr 05 at 12:34 PM

How to modify the simulation so that the ASRS moves each item in Queue immidiately before moving on to other actions? Is there a way to adjust the prioritization algorithm to consider the smaller item due day value first?Thanks.

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Felix Möhlmann Rykou commented · Apr 05 at 12:43 PM

Hm, I originally already had this in place but then decided to remove it because I didn't think of the cause when the preemption wouldn't suffice. You can modify the code to always return a very high priority if the item is picked up in Queue1.

TaskSequence.Task loadTask = taskSequence.tasks[2];
Object item = loadTask.involved1;
Object origin = loadTask.involved2;

if(origin.name == "Queue1")
{
    return INT_MAX;
}

return Model.time - item.duetime;

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Rykou Felix Möhlmann commented · Apr 05 at 03:25 PM

Thank you for your response and suggestion. I'll try it.

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