BTE for
Equivalence Numbers of Master Settlement Units 
Use
When you change a row of the assigned settlement units for a master settlement unit in the table control in transaction FO61U or FO62U, a BTE (Business Transaction Event) is called up.
This allows you to actively change the equivalence numbers using one of your own function modules (copy of function module SAMPLE_PROCESS_00702402). This sample function module contains instructions for linking the BTE.
If the BTE does not offer you the options you need, you can use the similar function module RESC_CHANGE_MASTER_SU_EQUINUM; however, this function module must be called up from your own customer program. For an example, refer to the function module documentation.
You can also call up the function module from outside R/3 using a BAPI.