Start with the question
Write the decision in one sentence. Are you reviewing revenue collected, invoices raised or orders placed? These are different measures. Make the definition visible before comparing totals.
Check the shape of the source
Look for missing dates, duplicate identifiers, incomplete categories and mixed units. A list of exceptions is often more useful than a single quality score, because it tells someone what to review.
Follow one record back
Choose a record from the summary and trace it to the source. Confirm its date, category, amount and status. Repeat this with an unusual record, not only a record that looks normal.
Make your assumptions readable
Document what you excluded, what you grouped and which period you used. Someone reading the report later should be able to reconstruct the meaning of the total.
Keep the review human
A validation rule identifies something worth inspecting. It does not explain every exception. Keep original data available and let an accountable person decide what needs correcting.
TAKE THIS WITH YOU
A good report starts with a clear definition, a visible source and a small list of exceptions someone can act on.