When do I have to update my model set?

Do I have to update my model set if I update my models (like downloaded a new FLAI, BB, or X-IVAP version)?

Short answer, most likely "yes"

Details:

swift uses the models you have specified in the model set
If an update contains new models and you want to use those, you need to add them to your model set
If models have been deleted, you need to delete those from your set
It can happen new models are available but those data are not in the swift DB yet. You can help to provide those data or wait until those are available.
It is a good idea to use model validation to detect inconsistencies / errors in your model set, see this page.

Other reasons when you have to update your model set