Using Events 
An event is created from any application program and published system-wide. Any number of receivers can react to the event.
Integration
The application in question must cater for the actual creation of an event.
Caution
Ensure that the event is not created before the relevant object is written to the database. Otherwise a workflow could be set to status error when started because the object required cannot be found.
Prerequisites
Events that you want to use must be defined as components of an object type.
Note
You can extend an object type on a customer-specific basis using the delegation concept by adding more events. You must then also cater for the creation of these additional events.
Features
Events are published without the creating application knowing whether a receiver reacts to them. The event manager checks whether there are active linkages for the published event.
An event can be used as follows in SAP Business Workflow:
As a triggering event of a task or a workflow.
When the event occurs, the task or workflow is started as a response.
As a terminating event of a task.
When the event occurs, the task is terminated as a response.
In workflow definition steps of the types event creator and wait for event.
The workflow system creates type linkages for triggering events when they are defined. You must activate the type linkages for the event manager to include them in its check. With steps of the type wait for event and steps that refer to a task with a terminating event, instance linkages are created at the start of execution, which are activated automatically. Steps of the type event creator publish events when they are executed.
In its event container, each event has information about the context of its creation, which is available to the relevant receiver. The information can be used for event-driven control and communication mechanisms.
The most important event parameter is the reference to the object whose status change the event announces.
Activities
If you use events only within SAP Business Workflow, the linkages required are created automatically by the workflow system. You can edit existing linkages in order, for example, only to react to events with particular conditions.