Why we started with the ledger
Most businesses we meet are not short of software. There is a stock app, an invoicing tool, a payroll service and a folder of spreadsheets holding the gaps together. What is missing is a single place where those numbers agree with each other.
So we build outward from the books. Purchasing, selling, stock and production are treated as the places where accounting entries originate, rather than as separate systems that finance has to reconcile afterwards. It is a slower thing to set up and a much faster thing to live with.
If a number cannot be traced back to the document that created it, it is an opinion.
The rule we design against.