The concept of the charge plan is fundamental in SAP CC Core Server. You build up a charge plan by listing all the charges that the end customer can subscribe to. Then you combine several charge plans and one refill plan at most in an external provisioning system. For instance, you can combine charge plans to build a commercial product in SAP CRM. Each charge contained in the selected charge plans are activated when a provider contract is signed with the end customer.
A charge plan is a reusable pricing block which is made up of charges. A charge contains one or more chargeable item classes (*) linked to a price plan. A price plan defines how to calculate how much a customer must pay to consume a service. This information is used to dynamically rate the price amounts at runtime.
A provider contract is the contract between a service provider and a subscriber. It is composed of one or several contract items which reference a charge plan or a refill plan. It is created and maintained by an external provisioning system and synchronized with SAP Convergent Charging through a dedicated technical interface (Web Services).
Accesses specify under which identifier the subscriber consumes the service. When SAP Convergent Charging is integrated with SAP CRM, the accesses are automatically created and maintained by SAP CRM. Note that a subscriber can access a service through various identifiers.
(*) Only if you price plan contains usage rate components. Chargeable item classes are not mandatory if your price plan only contains recurring or one-shot rates.

As of SP04, SAP Convergent Charging 4.0 features an allowance plan that defines the behavior of an allowance when the charging and refilling processes are executed. An allowance in a contract refers to an allowance plan at the most, and the allowance plan contains one to several customized allowance logic objects. A provider contract may contain zero or several allowances.
The following illustration shows the relations between the objects relating to allowances:

For more information on these objects: