Batch processing for several itemtype's, quantities and batch sizes?

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harish.varma asked Jun 5, '16 Brenton King commented Jun 7, '16

Batch processing for several itemtype's, quantities and batch sizes?

Arrival Sequence:

Items are sent to the combiner based on arrival sequence. First, 2 items (based on batch size) of type1 are sent to the combiner, are batched and sent to the first available W processor. Quantity column get updated to 4. The batch is then sent to the first available processor X, then to first available Y and to first available Z, and then to the sink. This process repeats until the quantity column for type1 reaches zero. Next, 5 items of type2 are sent to the combiner, are batched and sent to the first available processor W. Quantity column get updated to 3. The batch is then sent to X to Y to Z and sink. Since, for the next step to occur, 5 items of type2 are required for batching, but are not available (Quantity has only 3 items remaining), So only 3 items of type2 will be sent for batching. Quantity column gets updated to zero. Now, 6 items of type3 are sent to the combiner, are batched and sent to first available processor W. Quantity column get updated to 24. The batch is then sent to the upstream processors based on the sequence mentioned above. This process repeats until the quantity column for type3 reaches zero.

The processor processes one item at a time. The item is sent to the buffer of the upstream processor. The upstream processor waits for all the items to get queued, when the number of items in the queue

reaches the batch size, then the processing of the batch starts.

The processing time is same for all the parts. The setup times depend on the Low lot number. If low lot number is 1, the setup times are w=6,x=6,y=2,z=1. If low lot number is 0, then setup times w=2,x=2,y=2,z=1.

Software Version:

FlexSim 16.0.1

queue combiner batch

capture9.jpg (32.0 KiB)

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harish.varma commented · Jun 05, 2016 at 04:16 PM

@regan.blackett, @Brenton King @Jörg Vogel

Thanks for the quick response. The model behaves as expected, but if the batch is sent to the upstream processor, it should not be looped back to the combiner but instead be sent to the next upstream processor. I apologize for not mentioning the complete process flow. I am still having a hard time to assign the process flow to the items. I am new to the process flow tool. It seems to be a powerful tool for simulation. Please let me know if this is understandable. I tried my best to explain the complete scenario. Initially, I had been trying to simulate the problem according to Mr. Vogel logic.

Thanks.

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Jeff Nordgren commented · Jun 06, 2016 at 05:19 PM

Harish,

Can you send you model to us? Or have you solved this problem?

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harish.varma Jeff Nordgren commented · Jun 06, 2016 at 06:55 PM

Hey Jeff, I had not solved this model yet. Awaiting your feedback. I cannot share the actual model, as it is confidential. Thanks.

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Brenton King ♦ harish.varma commented · Jun 07, 2016 at 09:18 PM

Harish, did you know that you can lock an question so that only FlexSim employees can see it? Almost every model we work with is confidential. Some questions can be really difficult to answer without the model.

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Answer 1 · 2016-06-06T19:32:06Z

Regan Blackett answered Jun 6, '16 Ben Wilson commented Jun 7, '16

Harish,

Your expanded model doesn't really change that much about my original answer, but I redid the model with your new downstream processor scheme.

Attached are two versions of the model, one that works for a single sequence and then ends and another that anticipates needing to easily adjust the size and frequency of arrival sequences. Custom Combiner 2 is the simpler model, Custom Combiner 2-2 is a more advanced version that I'll explain below.

The component about actually putting the right things onto the pallets in the right order is the same for both and largely the same from the first answer from last week.

The first big change I did to the 2-2 version of the model was to change what a "Token" in Process Flow represents. In my previous answer, in order to do things quickly I had made each token represent a single pallet, but in light of your new information I found it was convenient to instead consider the Token to represent the arrival sequence. So in essence I have one Token representing all the flowitems in your item sequence table, and the Token knows who all the items in that sequence are based on the labels it is carrying. The individual items in the sequence are also placed on the list such that they are organized based on which sequence they belong to. This is a fairly advanced idea.

Because of the above changes I got rid of the Source objects in the 3D view and changed them into Create Object activities. I'm using what's called a Subflow to create all the flowitems associated with the aa, bb, cc groups from a global table, while also assigning them to the item list and putting references to them on the Token.

Then I let the Token, acquire the Combiner, create a pallet for the packing operation and do the same pull logic found in the previous answer. Instead of looping the same pallet back, I get the required items for the batch, send the batch to the immediately downstream queue, and now the Token, loops back, creates a new pallet for the next batch, and so on.

custom-combiner-2-2.fsm (35.8 KiB)

custom-combiner-2.fsm (31.0 KiB)

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harish.varma commented · Jun 07, 2016 at 05:33 PM

@regan.blackett

In my actual model, I have 318 item types. The combiner should not pack different item types on a single pallet. Each pallet should have a single item type with the respective batch size and be sent to the next processor. In your model a single pallet packs all the different item types. Expected process flow is - First pallet should have two itemtype1, sent to next processor. Second pallet should have two itemtype1 and sent. Third pallet should have 2 itemtype1 and sent. Fourth pallet should have five itemtype2 and sent. Sixth pallet should have three itemtype2 and sent, Seventh pallet should have six of itemtype3 and sent, and so on. Processing and setup times are not included. The setup times depend on low lot number.

I had been trying to simulate the model using flexscript, but now I feel the processflow tool is way better.

Thanks.

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Regan Blackett ♦ harish.varma commented · Jun 07, 2016 at 08:34 PM

So this is not the behavior you are looking for?

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custom-combine.gif (655.3 KiB)

harish.varma Regan Blackett ♦ commented · Jun 07, 2016 at 08:47 PM

@regan.blackett

This is exactly the behavior which I am looking for. I am using flexsim 7.7.4. I am unable to upgrade to the latest version. This was not the behavior which I had seen when I opened the model with 7.7.4. I apologize. Thanks

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