A system component is a key component that owns systems. Read more about the significance of system components here: Systems Datamodel and Terminology.
As there is no concept for System component in IFC 2x3, dRofus uses two ways of setting the system components for you. To keep total control of which occurrences that will be set as system components for imported systems you can manually classify Items with a system classification. Or, you can let dRofus automatically promote the first occurrences within the system as system component.
Set System component manually
In order to control which occurrences are set as system components its recommended that you use a classification in dRofus to define which occurrences are set as system components.