How to combine items by ASRS is rack?

[_3gsimulator]

[ FlexSim 22.1.4 ]

Hello users, I am building model of ASRS, but struggle with combining items (pallets, separators and boxes that arrive later)

1) asrs (palletizer) must distribute PALLETS on pallet positions (A1,W111,W151,etc.)

mix_autosave.fsm,

2) asrs (palletizer) must distribute SEPARATORS on pallet as a first layer on each positions (A1,W111,W151,etc.),

3) - this part works - and then boxes arriving from conveyor (IT STARTS TO ARRIVE IN FLEXSIM TIME 1204380), and each pallet should be loaded

4) when the pallet station batches the required number of boxes (W111 = 4 boxes, A1 = 4 boxes, etc.) palletizer should move whole pallet + all boxes in once, to the Output.

Please if you can give me a hint, how can I place a pallet always for the new batch of boxes and on top of this place separator as a first layer?

[FelixMoehlmann · Accepted solution]

I would use an Object Process Flow with the pallet queues as instances. This makes it easy to first have them pull a pallet and separator (and have the ASRS move those to them).

Then they can pull items of the correct type of a list until they are full and repeat from the beginning.

mix-fm.fsm

[_3gsimulator]

Thank you very much, so Object process Flow and pull from list. Please Felix, can you recommend me, what kind of Field priority should I use in List In case, I would like to send the box by label to any free pallet position?

I mean, the box A1 would be send to the first empty pallet (if there is not any other pallet already with other box A1). So the pallet positions would not be dedicated just for each type of box by label. Is it possible to do it just in list? Thank you

[FelixMoehlmann]

I'd use two separate Pull From List activities. The first pulls any item (with a low backorder priority). The token then continues down and pulls more items of the same type until the batch size is reached (with high backorder priority). In order to allow items to be pulled while the ASRS is still busy with the previous one I put the transport tasks into a subflow. The 'main' token creates a token in there and can then immediately pull another item, so pallets will first be filled up before another one can pull an item of that type.

mix-fm-2.fsm

[_3gsimulator]

Thank you very much @Felix Möhlmann i learned something new!

[_3gsimulator]

@Felix Möhlmann Hi Felix, I made everything as you mentioned, but when it come to chnage number of Count, the token can't be sent to next activity and increment label by 1.

It happens with first arrival of boxes (both are the same Type), but they go to different pallet due to the Counter value. I don't understand what is different from your model. Please can you have a look?

The first boxes arrive in 4300

Feroll_NO_position_defined_10.11-16.11.22.fsm

[FelixMoehlmann]

You didn't set the Back Order Queue Strategy for the list which gives tokens with a higher prio label priority. So the older request from the other slot gets to pull the second item.

[_3gsimulator]

Dear @Felix Möhlmann I have last question about it, can you please give me advice. I have only 1 buffer and 1 output. My forklift is available only 5 min. every 30 minutes. So in time 4800 buffer gets block.

I need to optimize the machine and in this moment when it is blocked, ASRS must continue to do different job.

But how can I add in decision point if the Photo eye (buffer) is blocked, then continue to other work by priority and later when it is clear again, load the pallet and unload on buffer?

Thank you for advice, if you know.

Feroll_NO_position_defined_10.11-16.11.22_autosave.fsm

[FelixMoehlmann]

The simplest approach might be to just wait for the first conveyor section to be empty every time.

feroll-no-position-defined-1011-161122-fm.fsm

The expression to read the photo eye state (or the state of other objects) would be the following:

Model.find("Buffer 1").as(Object).stats.state().value == STATE_BLOCKED