Access to the Personnel Calculation Schema Editor 
Procedure
You can call up the editor for personnel calculation schemas (abbreviated as the schema editor) as follows:
Direct access
If you know which schema you want to display or edit, you can access the schema editor directly. You can do this as follows:
The Personnel Calculation Schemas: Initial Screen appears (also called initial screen).
Indirect access from Customizing (IMG)
If you call an action in Customizing for Payroll or Time Management, and you want to maintain a schema for this action, the schema editor is called. You access the initial screen of the schema editor, and see that the name of the schema relevant to the chosen Customizing step is in the Schema field.