topic Batch size in FlexSim Forum

Batch size

TalHzf — Wed, 14 Dec 2022 18:47:03 GMT

[ FlexSim 22.2.2 ]

Hi all,

This is the modell I am working on it, the Products have rework process which is already done.Now I need to tell the machine that the products are two by two or 3 by 3 or 1by1 on machines worked.

In my simulation all item are worked one by one but I need that:

The Item 1 and 2 should be on Processor1 two by two worked but the item 3 should be one by one worked.

The Item 4 should be on Processor2 3by3 and Item 5 2by2.

All Items should be worked on Processor 3 with the same defined Quantity on The processors 1 and 2.

The time given in the table are just for one item on the machine so they should me multiplied.

Thank you.

Modell Batch HT.fsm

Re: Batch size

ralf_gruber — Thu, 15 Dec 2022 02:16:29 GMT

Hi TalHzf,

just to understand correctly: you need your items to be processed in batches but the process time is still per item in the batch? What is the batching logic in the queues before? Does the first available item in the queue start a batch with its item type and waits for completion of the batch, or is the batch with that item type taken first, that is completed first? Depending on your answer, I would try either a combiner in batching mode or even easier, just use one queue per item type and use the batching function of the queue object.

On another note: Your model seems to rework every single item. Should there not be a distribution deciding on rework based on a percentage?

Re: Batch size

TalHzf — Thu, 15 Dec 2022 19:35:26 GMT

Hi @Ralf Gruber ,

Yes, my items have to be processed in batches the process time is still per item.

The reason of the batches is because my items are processed on fixtures, and every fixture contains 1,2 or 3 same items.

For this Question "Does the first available item in the queue start a batch with its item type and waits for completion of the batch, or is the batch with that item type taken first, that is completed first?"

I can't send one item to processor and wait for the second to complete the batch, they have to be send both at the same time, the whole batch should be send to machine.

In my case I don't need to wait for item in queue because I suppose that I have not out of stock items and they are always available.

I didn't understand the last question.

Thank you so much.

Re: Batch size

moehlmann_fe — Fri, 16 Dec 2022 07:26:53 GMT

From your initial description, it seems that the batch size for a given type is fixed across all machines (Type 1 and 2 are always processed in batches of 2 for example).

Under that assumption, couldn't you just define that each object in the simulation represents one full batch of that size and adjust the processing times accordingly?

It would make it necessary to adjust the measured throughput values (if they are used as a result from the model). But that can be done easily after the fact and you wouldn't need to implement any additional flow logic in your model at all.

Re: Batch size

TalHzf — Sat, 17 Dec 2022 14:53:55 GMT

Hi @Felix Möhlmann ,

I get what you mean and I have already try it but just I need to multiplicate the outputs at the ende.

Is there any possibility to do it?

Thank you.

Re: Batch size

moehlmann_fe — Mon, 19 Dec 2022 11:03:24 GMT

You could simply place a separator at the end of the chain (between processor3 and the sink) that creates additional items depending on the original item's type. That way, the actual amount can enter the sink and be counted toward the statistics.

Alternatively, you would alter a statistics collector or complete a new one from scratch that multiplies the throughput/input by the relevant factors.

If you need more help, it would be good to know what statistics you are trying to get from the model.

Re: Batch size

joerg_vogel_HsH — Mon, 19 Dec 2022 11:26:26 GMT

Answer updated.

Re: Batch size

TalHzf — Mon, 19 Dec 2022 11:42:12 GMT

Hi @Joerg Vogel and @Felix Möhlmann ,

Thank you for the answer.

I need to know how many items I can produce per day.

So when I use the separator, I don't know how to tell it that it should multiply the the Items 1,2and 5 with 2 and item 4 with 3.

Thank you

Re: Batch size

joerg_vogel_HsH — Mon, 19 Dec 2022 12:27:58 GMT

@TalHzf ,separator property pane has a Quantity function field. The return instruction value is responsible for in how many parts an item gets split. You have somewhere the data of this in relation to an item Type label. You will collect this data by reading for example row and column of a table to get a table cell value, which you add as a return value. If you have already those values as label at hand in your item you can read that value and return it. If you prefer a process flow you act on split-unpack-quantity event.

Re: Batch size

joerg_vogel_HsH — Mon, 19 Dec 2022 15:16:41 GMT

attached a model for demonstration by characters as Type

Split_by_table_lookup_and_strings.fsm

Re: Batch size

andrew_o2 — Thu, 22 Dec 2022 22:08:30 GMT

Hi @TalHzf, was Felix Möhlmann's answer helpful? If so, please click the "Accept" button at the bottom of their answer. Or if you still have questions, add a comment and we'll continue the conversation.

If we haven't heard back from you within 3 business days we'll auto-accept an answer, but you can always unaccept and comment back to reopen your question.