Audit tool cuts 383 entries to 25 with 11 rules

Accounting knowledge shaped three of the 11 rules, starting with threshold avoidance: when a company requires senior approval above a set amount, the tool looks for entries just below that line — within 5% of it — because people may try to avoid approval. The rule does nothing unless approval thresholds are supplied, since thresholds vary by company. A second rule pairs the days before fiscal year-end with large amounts, and it only runs when a fiscal year-end date is given.

The rare-account-pair rule relies on the observation that normal entries repeat a small number of account combinations; combinations appearing only a few times are worth checking. That rule only looks at how often a combination appears, not at specific account names, and it skips processing when the population is under 50 entries. The tool then adds up severity points — high 10, medium 5, low 2 — to order which entries to review first; the developer stresses these points are not a probability of fraud. The design deliberately leaves false positives in place, since legitimate transactions can also sit just under an approval threshold, and the developer explicitly declines to claim that AI finds fraud.