Events can be triggered within the SAP system by ABAP programs or at operating system level (by the .sapevt. program).
SM36 Define Background Job)
You define and schedule jobs in an SAP system in transaction
System . >> Services >>. Jobs >>. Define Job.
Related: Scheduling Background Job
Once the job has been defined (through interaction with the system, using a dialog work process), it exists as an entry in the scheduling table at database level. The background scheduler (ABAP program that the dispatcher starts in a dialog work process) eriodically searches this table for jobs whose start time is imminent or already past.
The background scheduler is classified as a time-controlled job scheduler.
The background scheduler’s runtime is controlled by the parameter rdisp/btctime, which has a default setting of 60 seconds. If a job is scheduled to be executed and a background work process is available, the background scheduler passes the job to be processed to the available work process. This in turn executes the job.
The parameter value rdisp/btctime = 0 disables the background scheduler, so jobs scheduled for a specific time cannot be executed.
SM37 (to monitor jobs)
What tasks does the task handler carry out?
The task handler coordinates activities within a work process. The work process and the user.s SAP GUI do not communicate directly, but through the dispatcher. The database is accessed through the database interface and the ABAP coding is executed by the ABAP processor.