Billing offers almost fully automated workflow. Once configured it does not require any manual operations, except cases where user decisions are required. For example, manual order approval in fraud screening or provisioning of resources that cannot be provided automatically, like voice services.
Workflow comprises orders processing, sending notifications, raising system events and calling their handlers, processing documents and similar operations.
The most useful way to modify workflow is setting conditions. This feature is available for sending notifications, applying promotions and orders processing. Using conditions you can make these operations more specific and flexible.