Picking multiple items (at once) on FloorStorage using crane

[sakamoto_ryosuke]

[ FlexSim 20.1.3 ]

@jason.lightfoot This question is related from this question. After crane puts 4 flowitems to the slot, I would like the crane to pick those 4 items from the slot and carry to Queue2. However, upon loading, I get error at the same time, the pickUpItems is returning 7 items where there should be 4.

Load_Unload_Gantry3.fsm

[jason_lightfootVL7B4 · Accepted solution]

There's nothing to stop you assigning more than 4 items per sloit at the moment which it sounds like you should - either by checking hasSpace() or some thing else.

You can also filter out of the the slotItems array those that are not yet located in the floor storage.

You could also just pull those that are stored in the slot by pushing to the list with a partition of the slot and then pull them off by partition instead of using the slotItems of the slot - which gets all the items assigned.

[sakamoto_ryosuke]

@jason.lightfoot Thank you for suggesting. But then, which solution do you suggest in my case? I don't have experience in these FlexSim Storage Management enough to choose which one is suited, and also to create the flow.

[joerg_vogel_HsH]

Internally there is a list, which manages the slot items. There are four states an item can be in. What you have to check is the state ”stored”. Until an item is released from the warehousing module you must check its state. Only storage items in the state stored are actually present in the slot. Only those can you transport.

You must accept that there is much more to learn about the warehouse module.

[jason_lightfootVL7B4]

Here's an example of taking the stack of 4 to Queue2. I removed the push to list on the sendtoPort and instead detect the slot entry in the process flow and push to StoredItems there, partitioned by slot. Then when the slot reaches 4 as before, I now pull from the StoredItems partition for that slot.load-unload-gantry3_jl2.fsm

[sakamoto_ryosuke]

@jason.lightfoot Wow! Thank you very much. I'll need to study what you did.

[sakamoto_ryosuke]

@Jörg Vogel Thank you for your comment. I totally agree with you, I need much to learn about the warehouse module. But I'd like to learn how to use them. From the online document I can understand what it is, but since I'm not warehouse specialist, I can't imagine how to make use of them.

[sakamoto_ryosuke]

@jason.lightfoot I've been running the simulation for sometime, but when simulation time become somewhere 1200s, even after 5 boxes are piled, crane doesn't pick up.

[jason_lightfootVL7B4]

Yes it still needs logic to restrict the pile to 4. Or is it unrestricted? If so should it then only pick up the top 4 or can it pick up 5 or more (in which case lots of references to '4' need to be changed) ? Or should it priortise pickup jobs so that stacks of 4 are removed before any additional boxes can be added to a stack of 4?

These are the types of questions for which you should have answers before you start modelling.

[sakamoto_ryosuke]

@jason.lightfoot Sorry for not clarifying. Pickup job is prioritized so stacks of 4 must be removed before additional boxes can be added to the slot where there is stack of 4. There will never be 5 boxes piled up.

[jason_lightfootVL7B4]

Perfect, thanks for clarifying. So the emptying tasks then need adding to a task sequence with a higher priority than the tasks for for filling the floor storage.

[sakamoto_ryosuke]

@jason.lightfoot I have already put the task sequence for pickup to higher priority. I set it to 1. Placing to the FloorStorage is set to 0. Should I make it more larger priority number?

[jason_lightfootVL7B4]

Yes - it looks like we need to preempt only if we want the next sequence to pick up the just created stack of four. Also - we were not changing the label recording the number stored in the slot when we pick them up. Both changes in this model.load-unload-gantry3_jl3.fsm

[sakamoto_ryosuke]

@jason.lightfoot Thank you for your great help! It looks good now.