Job Material Default Operation Logic

I have a question about how Epicor chooses an operation to associate a material entry with. It seems like Epicor usually defaults to the lowest numbered operation in the job if no specific operation has been linked to a material, but that’s not always true. I’ve been able to go into a job with multiple uncompleted operations and add a material and it will default to some operation other than the lowest numbered. For a time, I thought maybe it was because Epicor was defaulting to the operation that last had a material added to it, but I can’t always reproduce that effect. Sometimes material is added to the operation with the most materials in it, and sometimes it won’t do that. It matters to us because of how people are adding material. We want to be able to understand the logic to be able to explain it to our designers, for example. If materials are coming in purchased direct to the wrong operation, they will be directed by our receiving dock to the wrong location according to the Resource Group tied to that operation. We’ve lost shipments this way.