Are the two related i.e., if there is availability for standard award, is there availabilty for upgrade as well? Is it possible to have award availability but not upgrade availability? If they are related, do the Full fare and Select fare upgrades availability correlate with standard and saver awards availability?

I am particularly interested in international travel upgrades.

Apologies if this has been asked and answered earlier. None of my searches turned up answers to the above.

Thanks