Connection of External Systems 
You can integrate with external systems using Business Application Programming Interfaces (BAPIs), Remote Function Calls (sRFC, aRFC, qRFC), IDocs, and EDI.
The most common interfaces are also available in SAP NetWeaver Process Integration. You do not, however, have to use it to
connect to external systems.
Note
For more information about the most common interfaces in SAP Event Management and their optimization, see Interfaces in SAP Event Management .
For more information about connecting external systems, see SAP Marketplace at
For more information about XI, see Integration with SAP NetWeaver Process Integration or SAP Marketplace at