We've encountered an error where an assembly used the same item multiple times in excess of the bill of material, duplicating the lines that got posted with that assembly and generating a double decrease for the items in question. The value of the end product didn't change, but the items consumed and the duplicates all have been used up in the assembly.
To have a better picture of the issue, I've enquire IV30300 (Inventory transaction amounts history), and noticed that all the duplicate items have 2 different transaction source (one of those lines have a blank trx source) and the line sequence number don't look right (original item and duplicate item have a difference between line sequence number of 1 instead of the usual 16384). Please see the result of the inquiry below for the assembly.
To get a better picture I've enquired BM30200 (Assembly Transaction History) and BM30100(Assembly Batch History) with the filter on the two transaction sources and it looks like one of the transaction sources appear on one table, but not the other (BMASM00002207 appears in BM30200 and BMASM00002289 appears in BM30100). See image below.
Now, the only way I can see that we can solve this is by creating a positive variance against all the items that have been incorrectly written off.
Is there any other way we could proceed? Also, does anyone know why this would happen and how to prevent this in future?
Thanks for your help.