I have a job where the backflushed pallets have double issued - req quantity 12, issued quantity 24.
I have seen this in a previous life and it turned out to be a bug, where the operation the backflushed material was tied to also “doubled” in quantity.
However, the job I have now does not show the backflush OP nor the Time and Quantity OP doubled. Peculiar to me, the backflushed part is tied to a Time and Quantity OP and not the Backflush OP.
What could be causing the backflushed material to issue twice with each trx?
Backflushed operations is not the same as backflushed material.
Backflushing operations completes operation when a subsequent operation is finished. For example, If you have 3 operations, but they are done by the same person at the same time, instead of making them clock in and out of each operation, you can set op 1 and op 2 to backflush, then when they complete op3 there is a process that will automatically complete 1 and 2 for you.
Backflushing materials is on the material side and can be attached to any operation (other than subcontract) and will issue the material to a job when the operation is completed. The reporting type of the operation is irrelevant to this process. If the materials are set to backflush, and the related operation is reported, they will be backflushed. It will backflush the required amount for whatever quantity is completed on the related operation. So if you say you reported 20 of the operation, 20 units worth will be issued. Backflushing will over issue if you over report operations.
Now that we have the basics out of the way, you are right, it shouldn’t double. I have see it where the materials are set to backflush, and related to an operation, and then someone uses the backflush option in job closing. I do not know if this respects the backflush flags or checks against any already issued material, and we basically just decided to never use that after some issues, and instead issuing any missing materials manually. I haven’t looked at this in years though, so it might be changed/fixed. I’m vaguely remember putting in a ticket and got the dreaded “working as designed” answer.
Look at your Part Transaction History for the part and see when the ‘backflush’ charges of material occur. Are they at the same time or different times? Hopefully, the answer may point you somewhere.
