How to push objects to a global list in a process flow?

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Björn A asked May 26 2018 at 7:11 PM Matthew Gillespie answered May 29 2018 at 3:56 PM

How to push objects to a global list in a process flow?

rack-replacement22.fsm

Software Version:

FlexSim 18.0.3

process flow lists

rack-replacement22.fsm (57.8 KiB)

· 2

Björn A commented · May 26 2018 at 7:12 PM

Hi,

I'm relatively new to Flexsim but I've been getting stuck on this one issue pertaining to Lists in a Process Flow for the Task Executors (AGVs).

Basically I want to simulate an AGV-system that delivers sequenced items, moving from the Sequencing station on the left-hand-side across to the Assembly station on the right hand side (see attached model). However, in reality the items that the AGV carries are sequenced onto a pallet rack and because I want to also feature this pallet rack that needs to be fetched before the Assembly stations can be resupplied.

To make this container (the pallets) I went into the ProcessFlow and used the "Create Object" block and then "Push to List". I have two lists: the "SeqRacks" and "AssyRacks" that need to be global as both TEs will be accessing the Racks from both. But when I run the simulation the tokens get stuck on the initial Push to List.

The thing is that I create the object at the control points and then I set "Assign to: token.item" and when I'm pushing them to the list I put "Push value: token.item" and "Assign to: token.pulled". I got inspired by other sample models however in those the list is local and the initial object is "Created In: up(current)". So my problem is how I create the object at the specific control point to then push them to a global list.

As a beginner with Flexsim I would appreciate greatly how I could fix the problem or another way of accomplishing this task. Thanks

Björn

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Joshua S Björn A commented · May 29 2018 at 2:17 PM

When you push an item to a list, that token will stay at the "Push to List" activity till that specific token/item is pulled from the list, and then it can continue on to the next activity, so you need to separate the push to list from the pull to list token flow. Also on your "Create Rack3" activity you will want to specify where you are creating the pallet at or else it will cause problems with its creation.

Hope This helps.

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Answer 1 · 2018-05-29T15:56:48Z

Matthew Gillespie answered May 29 2018 at 3:56 PM

The Push to List and Pull from List activities by default make the token wait until something happens on the other side (something pulls the thing you pushed or there is something for you to pull). So to use these activities using their default behavior you need to have separate tokens/objects pulling than pushing.

However, you can override this default waiting behavior which is useful in some situations. On a Push to List activity you can stop the token waiting by checking the Use Max Wait Timer box and checking the Keep On List On Early Release box. This will cause the token to stop waiting and not remove the entry on the list when leaving the activity.

If you haven't already done so, I would recommend going through the tutorials in the manual that walk you through a lot of these list options.

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