Inbound Event Message Processing 
SAP Event Management ( SAP EM ) executes inbound processing of event messages to
Check the syntax (for example, is the weight specified correct?) and the technical definition of the event messages
Log the event messages
You can display the error list for inbound event message processing using the transaction /SAPTRX/ER_MS_LIST.
Save the event messages on the database
Convert external event codes for event messages into internal event codes, if you use external event codes.
Use the tracking ID to search for the event handlers that belong to the event messages
Use a rule set with its activities to trigger further event message processing in SAP EM
The system can also process event messages that have already been set to Inactive .
Example
For example, you can report damage to a shipment after the shipment has already been completed in SAP EM and the corresponding event handler has been set to Inactive .
Log the processing results in the application log in the event handler list
SAP EM:
Receives the event messages from the application system and from external sources (BAPI, IDoc)
Checks the syntax of the event message
Determines which event handlers belong to the event message
Processes the event message according to the activities in the corresponding rule set