Operation modes in SAP

Using the operation modes, you can adjust the type and distribution of the
work processes to the varying load distribution during the day. You can
also adjust the distribution of the work processes to business
requirements that only occur once. During the day the demand for dialog
work process is high an system response for dialog work process must be
fast. At night there are less users so system resources are not
utilized fully if a major percent of them is reserved for dialog work
process. By defining operation modes, you can change not only the total
number of work processes defined in the profiles, but also the type and
distribution of the individual work process types within this total
number. The switch between the work process types is performed
dynamically during the runtime of the SAP system. The switch is
triggered using a defined schedule. A reserved work process is not
immediately terminated, but marked for switching. This means that
certain delays may occur. This type change is logged in the system log.
During the switch of the operation modes, neither the instance nor the
affected work processes need to be restarted. This means that the
quality of the buffer of the SAP system is retained during an operation
mode switch ,and that the request that is currently being processed by
a work process is completed. The individual work processes retain their
process ID after the switch, which can be observed in the process
overview (SM50).You can trigger an operation mode switch from a program
that you have written yourself using a function module (RZL_PERFORM_BA_SWITCH)