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Lot Size Based Structure within Master Schedule

  • 26 January 2024
  • 4 replies
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  • Sidekick (Customer)
  • 11 replies

Hello IFS community,

 

I have a question regarding how the Lot Size Based Product Structure works. 

Here is a short summary of what I tested:

Product Structure  - Lot Size Structure – Anything bigger than 23 pcs should have Alternate “1” and anything smaller should use alternate “*”.
I then master scheduled 35 pcs of this part number in one day. My Planning details for lot sizing are set as follows: Max lot size set to 25 pcs (no min or Std).

Result – Two Shop Order requisitions: 1 with 10 lot size and one with 25 lot size but BOTH with alternate 1 (only for lots bigger than 23).

 

EXPECTED result: Two Shop Order Reqs: 1 with 10 and one with 25 but with different PRODUCT ALTERNATES.

 

In this case, we are trying to tell IFS to use a different packaging for when we make 25 pcs Lot size.

 

I read in the link below that only MRP checks through Lot Size Based Product Structure:

Selecting Product Structure Alternate while performing MRP/MS in App-9 | IFS Community

 

Is this true or am I facing a bug? And if it is true, what could possibly be the reason why when I set all the lot sizing rules (structure and planning) that I would not be able to use such a feature!?

Why wouldn't MS also check through such configs?

 

I hope I can understand this better with your help. Thanks!

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Best answer by majose 29 January 2024, 15:51

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4 replies

Userlevel 6
Badge +13

@Guto Lot Size based Alternatives should be fetched when the SO or the SOR is created. It is not only limited to SORs created by MRP, it works for MS too and even if you create a SOR manually.

So what you described is not in order.

There is a check box, in Lot Size Based in the Detail tab. Just check if it is true. Just to make sure the alternate is picked as per the Lot Size based Alternatives rule.

You can process the SOR check if the correct alternate is picked when the SO is created. If not try Update Materials and/or Operations > Update Structure Alternate for Lot Size. Based on the result, the issue can be narrowed down.

Hope this helps !

Userlevel 6
Badge +12

Hello,

When Master Scheduling (MS Level 1 calculation) creates master schedule receipt, it actually creates the MS receipts into the tab Sub MS Receipts (and the main reason for this is max order lot size rule => system might need to generate more than one MS receipt per day)

Anyway, when doing this we capture structure revision, structure alternate, routing revision and and routing alternate (using for example lot sized based structure rules). This is then used when MRP explodes Master Schedule receipts, to save valuable execution time for MRP engine.

When MS Level 1 calculation runs, Structure Revisions and Structure Alternates etc, are refreshed outside Planning Time Fence (PTF). Look at my two yellow marked lines outside PTF. Here I have the same setting as you have. (Ignore values inside PTF, I was playing around here).

As times goes by, my proposed MS receipts will roll inside PTF and become fixed MS receipts… and then, when they are inside PTF, we don’t refresh Structure Revision, Structure Alternate etc. That’s how it is.

But, you might log an idea for this. I am actually open to have a command that could refresh the revisions, alternates etc based on new settings.

Regards

-Mats

Badge +5

Hello,

When Master Scheduling (MS Level 1 calculation) creates master schedule receipt, it actually creates the MS receipts into the tab Sub MS Receipts (and the main reason for this is max order lot size rule => system might need to generate more than one MS receipt per day)

Anyway, when doing this we capture structure revision, structure alternate, routing revision and and routing alternate (using for example lot sized based structure rules). This is then used when MRP explodes Master Schedule receipts, to save valuable execution time for MRP engine.

When MS Level 1 calculation runs, Structure Revisions and Structure Alternates etc, are refreshed outside Planning Time Fence (PTF). Look at my two yellow marked lines outside PTF. Here I have the same setting as you have. (Ignore values inside PTF, I was playing around here).

As times goes by, my proposed MS receipts will roll inside PTF and become fixed MS receipts… and then, when they are inside PTF, we don’t refresh Structure Revision, Structure Alternate etc. That’s how it is.

But, you might log an idea for this. I am actually open to have a command that could refresh the revisions, alternates etc based on new settings.

Regards

-Mats

Hello Majose,

 

thanks for your input. So it is not a Bug and I am not missing anything on my system configuration, right? IFS is simply not programmed to work as I described. Correct?

 

In our business case, this feature would be interesting to have. We want individual units ( lot sizes smaller than 23) to be packaged individually and bigger lots to be packed in 25 pcs boxes. 

Do you think it is odd that I am trying to do this with a master scheduled part? Is this not the industry standard? 

You also mentioned that I should log this idea. Do you mean I should open a ticket? :)

 

Anyways, you were already very helpful with your explanation. Thanks!!

Userlevel 6
Badge +12

WOW - I digged deeper into this, and in my first reply I focused sooo much on how MS drives component demand in MRP using the Sub MS receipt.

NOW I realize we have a bug in MS how we generate the alternative no:s in the Shop Order Requisitions created when we have lot sized based structures.

Report a ticket!

Sorry for the confusion @Guto 

Future glory ahead

-Mats

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