ABAP Class /SAPAPO/CL_RRP_FIX 

You use this ABAP class if you used fixed pegging in an ATP or CTP process.

With this ABAP class, as a first step the system checks availability against fixed pegging. In the process, the requirements that are assigned to a receipt element via fixed pegging are confirmed accordingly. If there are no fixed pegging relationships, in a subsequent step the system confirms the requirements according to the results of the net requirements calculation and creates fixed pegging relationships for the assignments. These fixed pegging relationships are always taken into account by the system. If the sales order is changed (due to a date/time postponement or quantity increase, for example), the assignment between the requirement and the receipt element is always preserved, since the system retains the existing fixed pegging relationship. In the case of a quantity increase or reduction, only the pegging quantity is adjusted. The fixed pegging relationship is not changed as a result.

If there are several schedule lines for a sales order item (due to partial delivery, for example), the system creates the fixed pegging relationships for the assignments according to FIFO logic.