So I need to upgrade ADManage Plus and ADAudit Plus to the latest versions, we're a couple versions behind but I've never done it before.  This is a 24/7 kind of place and I can have no downtime without a good reason (and an explaination).  I need to do the upgrades, but what kind of effects can I expect on the domain?  If it's just "can't use while updating" then that's an easy thing to schedule, but if it's a "can't login to domain computers/things don't work right" I need to plan extensively.  What is everyone's thoughts here?  

Thanks!