Do the updates have to be done in close proximity?

Q: Does the OS Update on the exchange servers(step 1) have to happen in close succession to the updates on the clients(2) , CDO(3), Calendar tool (4), or can it be scheduled a week in advance and just keep 2,3, and 4 as close together as possible?
A: You can have space between 1 and 2, 3 and 4 but the order needs to change. OS update on Exchange servers (1), a week, OS update on clients (2), Calendar rebasing tool run (3), CDO update for Exchange (4). Keep 2, 3, 4 as close as possible. The reason for moving the CDO patch is that we discovered an issue with scheduling appointments within OWA.