These unnecessary steps take additional staff time and cost you money without bringing a corresponding benefit. She told him her Mother always fixed ham that way. She said that her Mother had always cut both ends off the ham too. Over and over, I see companies with procedures held over from the days before computerization. The paperflow hasn't changed since the time paper was the only record of each transaction.
Many distributors keep invoice copies even though they can be reprinted at any time.
I have even seen a few companies that keep copies of the customer statement and mark each payment received on the copy. This made sense back when the 'statement' was actually a copy of the customer's ledger card and payments were posted to the card. Today, inquiries in the system tie all this information together. The packing list can be filed in Receiving and the vendor invoice can be filed in Payables. The new software release also has a Purchase Order reprint function, so you won't need to keep file copies.