Instance Profile: Changing Instance Parameters 
Purpose
To change a parameter value for an R/3 instance, you must identify the instance profile used at startup time.
Process Flow
If you want to increase the number of work processes provided for background processing, the name of the start profile file should end with
_<hostname> .If an instance profile is used by several instances, profile changes will have an effect on all these instances. In this case, the name of the start profile file should NOT end with
_<hostname> .