After you have defined an event, you can use the event you have created in one of the following ways:
Assign the event to a specific business object event.
Call the defined event from your source code using the Backend Event Publisher API.
See Using the BEP API.
Publish the event from workflow user decision steps.
This functionality is intended for ABAP developers who want to implement and use BEP in workflow user decision steps. For more information see Sending Notifications.