Customer exits in the inbound function module allow customers to:

• Change the way SAP segments are processed, e.g. by changing the value of some of the fields
• Access the customer segments they added to the SAP IDoc using the IDoc definition tool

The following points should be fulfilled by the customer exits:

• Can all the data in SAP segments in the IDoc be read via customer exits?
• Can all the customer segments in the IDoc be read via customer exits?
• Is a customer exit called every time a segment has been processed?
• Does the customer exit support error handling?
• Can the exit fill the parameters Workflow_Result, Idoc_Status and Return_Variables?
• Is there a customer exit for serialization?
• This makes sense if the inbound function module does not support serialization.
• If the customer has appended fields to an SAP table, are these fields easily accessible in the exit?
• Are the exits long-lived? Customers expect exits to be called with the same meaning in future releases.
• Is it easy for the customer to navigate through the data in the exit? For example, to determine which item is being processed now, etc.
• If the same coding is used for different message types: Can the customer tell which message type is being used?