Upgrading of BIG-IP 3900 systems

Hi all, we would like to upgrade the software of both our new BIG-IP 3900 Series for the 1st time. We have a concern if the service would be working after the update.

 

Are we able to update the software on one of the Primary F5 system and monitor it for one week then if there's any issue before upgrading the other Secondary F5 system ?