Maintaining an Event Receiver Linkage 
The event
created of the object type FORMABSENC is a triggering event of the workflow template 30000015 and, as such, is entered in the type linkage table as standard.Procedure
In order for the workflow template to actually be started, the linkage between the triggering event and the workflow template as the receiver of the event must be activated in SAP Business Workflow Customizing.
(Alternatively, you can activate the event receiver linkage by processing the workflow template
AF_process directly.)