Recurring revenue.
WHAT THE ENTITIES ARE
Customers Subscriptions Plans and prices Invoices Payments Credits and refunds
WHAT MAKES IT DIFFICULT
Subscriptions change mid-period Payments fail and retry Discounts apply variously Cancellations may be immediate or at period end Invoices may be paid partially
WHAT TO MODEL EXPLICITLY
Subscription state over time, with validity periods.
WHY
It is the only way to answer what was active on a given date.
WHAT RECURRING REVENUE MEASURES REQUIRE
A clear definition of what counts, and at what point.
WHAT TO AGREE
Whether trials count How annual plans are apportioned When a failed payment stops counting How upgrades and downgrades are treated
WHY AGREEMENT MATTERS MOST
These definitions determine headline figures, and disagreement is common.
WHAT CHURN REQUIRES
A definition of when a customer has left.
WHAT TO DISTINGUISH
Voluntary cancellation from payment failure.
WHY
They have different causes and different remedies.
WHAT TO RECONCILE
Revenue figures against the billing system and the accounts.
WHAT TO NEVER DERIVE FROM
The current state alone, which loses history.