How does Goods Issue know which Batches to deallocate from A/R Credit Memo?

Question

Hi,
I am creating an addon that runs after a A/R Credit Memo is created.  It creates a Goods Issue, and enters the Item Code and the Quantity from the line items on the Credit Memo into the Goods Issue.
After it writes the Goods Issue to SAP, I open up the document it created and see that the line items are in there correctly, and that somehow the batches assigned to those line items are also in there.
There is nothing in the code that does anything with the Batches, but somehow SAP knows which batches to work with.
I haven't been able to find any info about it.  Can you please help us understand what is happening?  How does SAP know and make assignments to batches in line items in Goods Issues?
Thank you,
Mike

Answer 1

Hi Michael and Gordon,
Sorry Gordon, I'm quite sure you misunderstood Michael original question. Michael asked how the add-on he created could link corresponding batch number from an A/R Credit Memo document could be selected by Goods Issue document which generated by the add-on, while he actually never wrote a code to select any batches numbers which available in the system.
Maybe a little bit of illustration:
1. Item A, qty 10 - (batch A qty 5, batch B qty 3, batch C qty 2)
2. A/R Credit Memo occurred, return of Item A with 3 qty (batch A qty 1, batch B qty 1, batch D qty 1). Therefore, item A latest position should be (batch A qty 6, batch B qty 4, batch C qty 2, batch D qty 1). This A/R Credit Memo created by add-on.
3. Goods Issue document triggered by add-on. The problem is, Michael never write any code to select any batch numbers, and somehow the system choose batch number precisely as occurred in number 2 (A/R Credit Memo document), which is (batch A qty 1, batch B qty 1, batch D qty 1). Therefore the stock position for Item A back to as being displayed in number 1.
I believe this shouldn't be possible at all. Unless, there is a certain mechanism in SAP that automatically choose batch number to used in Goods Issue document using LIFO (Last In First Out), which is, as far as I know never exist in any SAP B1 version. Yes you could automatically choose batch numbers according to available batch, but you could do this when system prompt you when you tried to issue certain document using SAP application itself, not using add-on.
And of course, you could write a code to choose certain batches based on certain A/R Credit Memo, but still, you need to write a code, you can't do this without a code, selection of batches is compulsory when you tried to add a goods issue document which consist of items that managed using batches.
In my opinion, I think it is better for you to re-write those codes and relate batches you want to attach with your Goods Issue document based on corresponding A/R Credit Memo. It is much safer, and the error message you encountered won't happen again in the future.
Best Regards,
Hendry Wijaya