There is a quick way to populate new instances while working on the definition of operation modes. I used to create each instance manually, specifying the profile names and other information. However if the instance is active (and instance profiles were previously uploaded in transaction RZ10) you can have the system do it for you. This saves a lot of time, for example, after adding several dialog instances to a system.
Call transaction RZ04 and use menu Operation mode -> Maintain instances -> Operation mode view, or use button Instance/operation modes
Then use menu Settings -> Based on current status -> New instances -> Generate
The new instance will be added to the list and all operation modes assigned to it. Now you can work on the work process distribution or each operation mode.