Before you create a processing mapping, activate DataSources in SAP. You can also customize whether DataSource fields are visible. Use the following SAP transactions to activate DataSources and customize DataSource fields in SAP:
RSA5 Transfer DataSources function.
Changes the status of DataSources from Delivered to Active.
RSA6 Postprocess DataSources and Hierarchy.
Customizes the visibility of fields in a DataSource.