A custom billing variant program is needed to determine IF there is an active pipesafe contract (division 05) on the customer account. The custom billing variant will be added to the rate steps of the quarterly rate. Copy existing standard function module "ISU_COMPUT96". The custom variant program(function module) could use the structures that the standard function module provides. Each time the billing engine is executed for a contract, it will execute the variant programs assigned for the rate. Enhancement will be called during transaction EASIBI. IF the function module finds a contract with a division 05 in the search - pass back numeric value factor 1 ot the output variable - MAC_OUTPUT_IOPER X_OP-01 ELSE pass back balue factor 2 to the output variable.
Please experts I need help with this, I have no experience working with billing I just have some presentations about rate building and I don't know how create custom variants and how link them with a function module, if anyone has some material or point me in the right direction it will be a great help, thanks in advance.