A quarter of supplier invoices, 150 PDFs with every supplier in its own format, the price lists agreed with each one and the warehouse receipts from the ERP. Until now only the totals were checked. Esan reads all 974 lines against the price in force that day, the discounts, the freight terms and what actually arrived, and finds thirteen overcharges at four suppliers: €2,535.44 before VAT, from 200 kg billed and never delivered to a delivery note invoiced twice. It leaves an Excel with the proof of every case and a claim to each supplier as a draft in Outlook.