What configuration needs to be performed to avoid the creation of new employees after data...

Enable the Employee Subgroup (ES) switch in the Personnel Action Types in the Set Up Personnel Actions configuration step.

Update the feature for defaulting employee numbers (NUMKR) for internal number assignment when hiring new employees.

Maintain personnel number ranges with the external number range switch.

Populate the key mapping table with the mapping of PERNR IDs in SAP SuccessFactors Employee Central to SAP SuccessFactors Employee Central Payroll.