BUG? Pull from list, pulled QTY changes based on forklift copies in the model.

[ad6367]

So like stated in the headline, I have a problem with pulling from the list

In my model I have:

1. A source creating pallets into queue

2. Queue pushing them to list "pickpallet"

3. In process flow, I have a Pull from list (pickpallet) with request of 1 and required of 1.

4. After that I have Acquire to acquire resource wich is a group of transporters

5. Travel to queue->Load item pickpallet

6. Run subflow for picking

An so on..

I also have a parameter table with reference of he transportation group "copy and delete group members", from where I can change the amount of forklifts. This works as it should, creating and deleting forklifts.

The problem is that the pull from list should pull only 1 entry for the token, meaning 1 picking pallet for the forklift to go and pick up boxes on it, but the token pulls more than one entry and the quantity of pulled entries goes hand on hand with the set quantity of forklifts on parameter table.

So basically if there is only one forklit, all is good, if there is 2 both of those forklifts will pick 2 pallets at the same time (The token pulls 2 entries), and 3 forklifts = 3 pallets, and so on..

This problem also occurred when I tried to create those pickpallets to the queue using process flow. If the set number of created pallets was 5 it created 10 if there was 2 forklifts on the parameer table.

I tried to recreate this problem into a very simple model with only these objects and process flow, but was not able to.

Here is a picture of 2 forklifts on parameter table and the forklifts picking up 2 pallets.

Here is a screenshot of the pull from list activity so you can see the pull request is only for 1 entry.

And here is the settings in the parameter:

Thank you in advance for the help! 

[FelixMoehlmann]

Did you build the logic in an Object Process Flow? Creating one token per group member per forklift would explain this.

[tilman46JJ4N]

Is this a bug? When I pull items from the list, the pulled quantity changes depending on the number of forklift copies in the model.

[FelixMoehlmann]

Can you share a screenshot of the token labels after the pull and the part of the model where the items are pushed to the list?

[ad6367]

I have used general process flow for all my processes this far.  And the pull from list activity is not on the same flow with the create object tokens made to create those pallets. If that's what you mean?  

[ad6367]

So you have the same problem? Have you found a solution yet? I have not.

[FelixMoehlmann]

I'm sorry but without seeing more of the model I can't say what else might be causing this. Can any of you provide an example model that shows this behaviour? Maybe remove any sensitive data from your model and upload it?

I have attached a very simple example model of how I would build the logic. Maybe you can check what is different in your models compared to it.

[ad6367]

Hi,

Thank you for the help already. I'm gonna be able to continue this tomorrow. I'll check your model and if needed, try to modify my own model so that I can attach it here.

[ad6367]

I have now prepared a shareable model which is attached.

The process flow logic is not similar as in your example, but maybe I can pick some parts from it which would work for me. 

In my model at this stage I have been able to create initial inventory for items (Currently enabled only for one item in process flow for testing purposes). Now I've tried o create a parts picking process from racks to picking buffer.  I try to create the picking system first with very simple way and only after that add more items and order types. For example, I don't know yet how can I handle the empy pallets from the rack in parallel to the picking, or if there is a order for full pallet qty, which would not need the picking pallet to be used.


From the model, you can see that the pulled qty of picking pallets changes with the forklift qty. I noticed that the initial inventory too is multiplying for some reason when I add or subtract Transporters from the model parameters. You can test this from the model.

In addition to this problem, please feel free to comment also the process flow and logic with the picking.  All help is appreciated 🙂
 
Thank you!

[FelixMoehlmann · Accepted solution]

The Process Flow somehow became a subnode of the transporter. Copying the transporter thus also copies the flow and all actions get triggered multiple times.

Move it back to the tools folder to fix this. You can use the following code line in the script console to do this.

Model.find("Transporter1").subnodes[1].up = Model.find("Tools/ProcessFlow");

Regarding your general question: When picking from pallets, the "Use First SELECT Value as Quantifier" option of lists can be useful. Rather than push individual items to the list, you give the pallets a label that shows how many items theiy contain and push them to the list. By using this label as a SELECT value, instead of the pallet being removed from the list, the label is decremented by the pulled amount. Only when label reaches zero is the pallet removed from the list and the pushing token continues. You can thus utilize this to know when a pallet will be empty after the pick.

I have attached a small example model for this. The pick token ends up with three labels: the pulled pallets, the quantity of items to pick from each (AvailableContent) and an array that denotes whether the pallet will be empty afterwards or not. This information could then be used to plan the pick/route.

      

[ad6367]

Thank you so much! That code totally fixed the original multiplying problem, so I accepted that as solution. 

For the general push the list-> pull from list, using the SELECT method, I still need to play around little to be able to figure how it works. Now I can only get the transporters to pick pallets from the rack and not boxes as the pallets (token.Pallet) are the objects pushed to the list.  How is it possible to pull only the boxes from the pallet and reduce the AvailableContent with Pull from list? I added the same model with this logic.

[FelixMoehlmann]

The idea is that you are pulling the pallet and the quantity to load from that pallet. With that information you can create an array of items to load.