Additional Information on Operation Mode Switches 
System Startup
When a server is started, it first runs without an operation mode. The number of work processes and their distribution is defined in the instance profile used to start the server.
The status of the operation mode is checked at regular time intervals and the operation mode defined as active in the timetable is activated automatically. If there is no operation mode for the current time in the timetable, an operation mode is not activated.
Initial Operation Mode Switch
The first time an application server is switched to an operation mode, this is done by the ABAP/4 program
SAPMSSY6 . This program runs cyclically, collects the alert values, performs profile checks and creates DUMMY operation modes. The profile parameter rdisp/autoabaptime controls what intervals the program runs at. The default cycle is 300 seconds.SAPMSSY6
only switches operation modes if the application server is not running in an operation mode. Normally, the system is switched within 5 minutes of system startup to the operation mode defined in the timetable.SAPMSSY6
does not perform a continuous switch. This means that a manual operation mode switch will not be switched back after 5 minutes.Timed Operation Mode Switch
The exact times for operation mode switches are defined in the timetable.
A timed operation mode switch is started by the job scheduler (
SAPMSSY2 ). The operation mode switch can therefore only be performed automatically if at least one job scheduler is running in the R/3 System. This means that at least one background work process and parameter rdisp/btctime > 0 must be available.The switch is always done for all servers defined in the operation mode.
If more than one job scheduler is running, only one job scheduler can activate an operation mode switch.
See also:
Switching Operation Modes