Further Issues

Before you start the implementation phase, you should keep in mind:

Releasing BAPIs

When you release a BAPI, it becomes available as a fully implemented method of a business object type. Releasing also prevents anyone making incompatible changes to the BAPI, because all changes made to a released BAPI are automatically checked for compatibility in the BOR and the ABAP Dictionary, and incompatible changes are rejected.

SAP internal: If the BAPI is only to be used internally, and therefore not for release to customers, the status of the function module must be set to Released internally.
The BAPI must be released in cooperation and agreement with the integration teams and with persons responsible for quality control in the development department concerned.

Enhancements and Modifications of BAPIs

If you are enhancing or modifying a BAPI, rather than creating a new BAPI, keep in mind the requirements below:
For more information, see
Enhancements, Modifications….

BAPIs Used for Outbound Processing

Up to and including Release 4.0 BAPIs could only be implemented as function modules in the same system that they were defined in.
As of Release 4.5A BAPIs can also describe interfaces that are implemented in a non-SAP system but that can be called from an SAP System. These BAPIs are known as outbound BAPIs and are defined in the BOR as API methods of SAP interface types. There are always separate systems for defining (client) and for implementing (server)
BAPIs Used for Outbound Processing.