When do you have electronic registrations and signatures and thus need to be in compliance with Part 11?

When you press the enter button and you save data to a hard drive or USB drive, of course depending on whether or not you have to follow predicate rules (predicate rules interpreted as GMP)

Can you e.g. have hybrid systems (paper and electronic systems)?
How do you ensure proper electronic archiving?
Biggest problem ensuring compliance with part 11 as seen from John Lee's point of view is print versus electronic versions.