Comment by tetha

From what I've learned from a few guys, double ledger accounting is a technique which optimizes for consistency, error detection and fraud detection. Each movement of money, or material should always be written down in two or possibly more places. Ideally by independent people or systems.

Once you pair this with another entity or company doing the same, it becomes very hard for money or goods to vanish without the possibility to track it down. Either your books are consistent (sum of "stock" + sum of "ingress" - sum of "egress" - sum of "waste" makes sense), or something is weird. Either your incoming or outgoing goods match the other entities incoming or outgoing records, or something is amiss in between.

This is more about anomaly detection, because paying a clerk can be cheaper than losing millions of dollars of material by people unloading it off of a truck en-route.