Generally spoken: facts contain timedependend operand values. Facts are always linked to one operand and depending on the operand type the information on the data base is interpreted differently. During execution of billing facts are read from the data base and interpreted as timedependend values for the input operands that are used in the executed schema steps. The screens to maintain the facts are the same regardless if they are called from installation, rate category or rate. For every operand type there exists one screen that is called if the facts shall be maintained for an operand of this type. So even if the data base structures are different the maintenance of operand values looks the same for all three levels. If for the same operand for the same period values are maintained on different levels (rate, rate category and installation), these values will be priorized in the following way:

• Installation facts have priority over
• rate category facts have priority over
• Rate facts.

This priorization is developed partly in function module ISU_RATES_COLLECT where installation facts and rate category facts are mingled into output structure xy_ifacts. The other part is done in function module ISU_OPERANDS_ANALYZE where also the rate facts are taken into account (see there)

Rate Fact Groups

For every rate one may create one or more rate fact groups. Every rate fact group contains just the input operands that are used in this rate. It’s not possible to add operands to the list of operands to be maintained in the rate fact group. The date base table for facts in rate fact groups is EKDI. The key for this table is the rate (TARIFNR), the fact group (KONDIGR), operand (OPERAND), season (SAISON) and the to-date (BIS). The maintenance of facts in a rate fact group is always done via the transaction to maintain the rate (EA30, EA31 and EA32). Before facts can be allocated to a rate fact group the key (KONDIGR) has to be provided in customizing table TE067 (in IMG via ‘SAP Utilities’ -> ‘Contract Billing’ -> ‘Billing Master Data’ -> ‘Rate Structure’ -> ‘Rates’ -> ‘Define Rate Fact Groups’).