Billing

Mocked: the entire Billing group — None of these three modules has an FBS, function list or ERD anywhere in the handover pack — they appear only as boxes on the context diagram, and other modules reference them as an interface they hand off to, never with a contract. The inputs below are genuine (real deal price lines, billed revenue rows and variances produced by Pre-Deal Simulation and Revenue Tracking), but every rule applied to them is our assumption and is labelled as such. Billing Core, Adjustment, Dispute and Backdated Transactions are not built at all, for the same reason.