I once assisted the introduction of electronic invoicing in a project. The customer required a certain EDI format but allowed (for a limited time) PDF invoices

I once assisted the introduction of electronic invoicing in a project. The customer required a certain EDI format but allowed (for a limited time) PDF invoices to be sent directly to a processor specialized in fully automated processing of legacy invoice documents. The PDF had to fulfill strict requirements, most importantly containing real text and not scanned images. As neither the EDI requirement nor the PDF format requirements could be met in time, scanned paper invoices were sent. Lo and behold, all invoices were paid in time. I never got rid of the thought, that the invoice processor, which, boasted their progressive fully automated analysis capabilities, was most probably a small army of underpaid humans. Didn't help that they were based in low cost EU country.