A system component is a key component that owns systems. Read more about the significance of system components here: Systems Datamodel and Terminology /wiki/spaces/WA/pages/1318361180.
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.
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Automatic setting of System component
If no Items have been assigned a system classification dRofus will promote the first member sin the IFCsystem as system component. The image below show IFCsystems and their components.
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In the above image we got in total 14 systems. The first system (“Mechanical Exhaust Air 8”) is expanded so we can see all members of the system. When importing the first system, the first member (“M_Exhaust Unit with Cabinet - …” highlighted in red) will be promoted as system component in dRofus. The same logic will be applied to all 14 systems.