Issue with ASRS & Forklift load unload

[nbh3741]

Hello,

I'm currently facing issues with my FlexSim model and would appreciate your assistance in resolving them. Specifically, there are three main problems:

1. Forklift Unloading Issue: The forklift is not unloading pallets to available queues; it only unloads to one specific queue.

2. AGV Unloading Issue: The AGV is not unloading pallets based on type (it only unloads to the first ASRS).

3. ASRS Pick and Place Issue: The ASRS is not picking and placing pallets according to available slots.

I've attached my model file for your reference. Could you please guide me on how to troubleshoot and fix these?

[nbh3741]

@FelixMoehlmann I'm waiting for your reply

[FelixMoehlmann]

In the Unload activities you are referring to fixed objects (Queue17 and InBound_Zone1_1). How you want to vary the queue in the first case is up to you. You could put them all on a list and pull a random one to unload to (leaving the queues on the list) or generate an index between 1 to 5 (either random or sequential) and then use "Object By Case" in the Unload activity. "Object By Case" is definitely what you want to use to unload based on type. The pallets do not come with a type label though, so that would need to be added first during their creation.

Nothing is being moved into the racks because their slots have a size of 1.25x1.3 while the pallets are 1.5x1.5. Since the Slot Assignment Strategy of the racks requires there to be enough space for an item, nothing is pulled by the racks.

[nbh3741]

I tried the solution you suggested, but I am still not getting the expected results.
Could you please provide further suggestions or guidance regarding the model?

Thank you for your help.

[FelixMoehlmann]

I implemented some examples in your model.

The PM_Queues are acquired as a resource and release when they are empty again. You could add an ORDER BY clause to the Acquire activity to control which queue gets acquired first if more than one are available. For example "ORDER BY RAND()" to choose a random one.

The pallets and boxes are assigned an SKU label when they are created. They are distributed to the inbound lanes based on this label (label value as group index of queue).

I change the size settings for one rack per lane to allow them to pull pallets. And I connected the ASRS to the queues and use the "Use Transport" option to have them move the pallets.

I also added a control area and changed the positions of the stations in the rework loop. This could otherwise look up the system because pallets from the rework loop had no chance to re-enter the main conveyor.

[nbh3741]

Thank you @moehlmann_fe for the quick response.

It’s working for a single rack, but not for double-deep ASRS.

[FelixMoehlmann · Accepted solution]

I don't know why it wouldn't work for more than one rack after adjusting the dimensions of the other racks and connecting them to the queue.

Though I would recommend to use a single rack whose depth is doubled instead of two separate objects. It simplifies a couple things, while being functionally the same (as long as the item and slot sizes are thus that 'merging' two slots doesn't change how items can be placed there).