As part of Import and synchronize Occurrences, systems in the IFC file will also be imported and synchronized.
To import or synchronize systems you need write access to the Systems module.
In order to import systems, all relevant Items needs to be created in dRofus first, as explained in .Items.
A system in the IFC will probably contain occurrences from different Items, so in order to make sure all Systems and Occurrences are imported it is an advantage to synchronize all occurrences of relevant Items.
Use the Category selector to determine which object you want dRofus to read from the IFC file
Press Synchronize with model
Select All Items in the filter drop-down menu