Sorting item from conveyor onto different pallet

[kags_j]

[ FlexSim 21.2.4 ]

Hello everyone,

I am currently working on simulation which requires the flow items coming from a conveyor to be sorted and loaded onto pallet (created in FloorStorage or Queue) based on their order number (flow items are created thru token and token have labels to identify the orders numbers). Once a pallet has reached a qty 10, then the pallet should be moved to Queue2. I have created basic framework but not sure how to proceed further, hoping to get some help from the community here.

Logic flow is as below

1.) Item reaches the end of conveyor

2.) Operator pick the item

3.) Move to FloorStorage1

4.) If no pallets are available, then a new pallet is created and flow item is loaded on it.

5.) Operator walks back to conveyor to pick 2nd item

6.) Operation Pick 2nd items and moves to FloorStorage1

7.) If the existing pallet has items from same Order Number and has Qty < 10, then the item is loaded on to the pallet else a new pallet is created.

8.) Once the pallet has 10 items it is moved to Queue 2 and the above sequence is repeated.

Pallet-Sort-Example.fsm

[moehlmann_fe · Accepted solution]

The floor storage is part of the warehousing system, so you can use the 'Find Item' activity to check if a fitting pallet is available. Note how the query parameter '$1' is assigned to represent the token, so that $1.item.OrderNum becomes token.item.OrderNum.

The label you want to check for can be entered in the Storage System properties. This allows you to index the label (massively increases search speed when you have a large number of items - not necessary here) and makes the label appear in corresponding pick options, such as the query field in the Find Item activity.

By setting a max mait timer of 0s, the token can be send to a 'Create Objects' activity, in case no pallet with the correct label value is found. The created pallet is assigned the item's 'OrderNum' so it can be found by the next token of that order.
After the item was unloaded onto the pallet, the token can directly check if the pallet is now full. If that is the case the process flow can dispatch a task to move it to Queue2. In the attached model I use an A-connection in the 3D-model for this. The floor storage is set to normally not release items, which is then 'overwritten' from the process flow. This has the advantage that 'releasing' the item automatically marks it as outbound in the storage system, so the 'Find Item' activity above will no longer find it, even if it is still waiting for the forklift.

pallet-sort-example-fm.fsm

[kags_j]

@Felix Möhlmann Thanks for your prompt reply, it's exactly what I wanted, works good. Only one problem is that, the Order Qty are not always multiple of 10, so if the order qty is 15, the last pallet would have only 5 items and they get stuck and doesn't move the Release Pallet stage since it is expecting the pallet Qty to be 10, is there a way to fix this?

[moehlmann_fe]

Instead of sending the tokens into a sink after the item was loaded onto a ballet you could batch them. The order quantity and number is available on the tokens already, so you can use those to have the tokens wait until all items in the batch were unloaded.

Then you can check whether there are any unreleased pallets. To do that I set a label on the pallet when they are released. If that label is not there, the pallet is still in the storage and can be released at that point. I put a zone with a max. content of one around the section. This is to prevent the possibility that two tokens release the same pallet. (The label will always be set before the next token enters the decide activity.)

pallet-sort-example-fm2.fsm

[kags_j]

Hi @Felix,

I was trying to add some more activities to existing file, I wanted to move the pallets from FloorStorage1 to FloorStorage2 once they have 10 contents on them, I noticed that the pallet gets stacked on one another behaving as if there is no items on top of them.

Once a particular order is completed (all items from that order is stacked onto pallets and have reached FloorStorage2), I wanted to move these items into Queue 2. But its not behaving as expected, would you be able to advise on how to fix this? pallet-sort-example-fm3.fsm

[moehlmann_fe]

This happens because, as you correctly described, items on the pallet (or 'inside' in terms of the simulation) are indeed not taken into account when determining if there is space in a storage slot or when stacking the pallets.

The floor storage only stacks items to the top of its bounding box. So i reduced the height of the first storage to 0.2m, meaning only a single pallet fits inside a slot.

[kags_j]

I figured by using the Sort Stacking options, i could prevent it. I am using the FloorStorage2 for some big items as well, so can't really use 0.2m limit on it.