How to move random batch size from a source to a combiner?

Question

question

Maria_susana Mn asked Sep 1, '22 Felix Möhlmann answered Sep 1, '22

How to move random batch size from a source to a combiner?

Hello everybody,

I am trying to model the number of Purchase Orders (PO) received in a company per month. Each PO can arrive any day in a 30-day period, and it could have a random size of items (material) that range from 2 to 22. I used the inter-arrival time (Batch processing) to mimic this behavior so that I could get at one event one PO of random size between 2 – 22 items in a cycle of 30 days.

Then, the next step I am trying to mimic is moving each PO of a different size from the queue into a combiner (keeping size intact), so they can travel together to the subsequent processes. Besides, in the same combiner, I would like to assign a specific process time to each PO, depending on its size. To combine all items, I know there is a trigger "on entry" (Update combiner component list) that can be used. However, I haven't found a way to make it work. Likewise, I'm struggling to assign the Process Time depending on the PO size. So I built a table for this purpose. However, still having issues with it.

I will appreciate any comment or insight on how to make it work. Maybe, there is an easy or different way to solve it. Thank you.

Software Version:

FlexSim 22.1.2

batching size

Answer 1 · 2022-09-01T07:21:26Z

Felix Möhlmann answered Sep 1, '22

First off, one general tip. The batch size is a whole number, as such you should use "duniform()" to randomize it (discrete-uniform).

What I would suggest is to have the container object (pallet, crate) determine the batch size. This makes setting the combiner properties a lot easier.

In the attached model I assign the "PO_Quantity" label to each created pallet. When they enter the queue, the event-triggered source in the process flow creates a token which in turn creates the specified number of boxes in the other queue.

The "Update Combiner Component List" option can serve as the basis for setting the combiner batch size. But since there is only a single input port for the boxes, it can be simplyfied. The label value of the pallet is copied to the relevant nodes of the combiner. A table is not actually needed.

To control the process time, you can use the "Values by Case" option. Again, the "PO_Quantity" label is the case function that controls the process time.

I didn't set up the "crate" source inter-arrival time yet, as I wasn't entirely sure what the desired interval is. In your screenshot you have the source set up to create a batch every 15 days on average. Though from your description it sounds more like you want to create one batch per month at a random point during that month. That behaviour would be easier to realise with a Date Time Source in Process Flow.

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