A deduction shows up when the customer pays less than invoiced and takes the difference: a promotion that was never applied, a price other than the one agreed, a shortage on delivery, damaged goods, a logistics charge or a service level penalty. The remittance advice arrives with the reason compressed into a single line and, more often than not, several items short-paid under one document.
From there the case moves from desk to desk: sales would rather not strain the customer relationship, accounts receivable needs the balance cleared, logistics holds the proof of delivery, and the window to dispute keeps closing.
The analysis gets assembled from the tools already on the desk: Microsoft Excel spreadsheets where each account manager tracks their own cases, email to chase a copy of the delivery note or proof that the promotion ran, and Microsoft Power BI reporting on the outstanding deduction balance. Each of those does a useful job on its own, and none of them records what was claimed, who gathered the evidence, what was negotiated, or under whose authorization the difference was closed.
The problem is not missing information: it is a monetary difference with no owner, no deadline and no closure anyone can defend to the customer.