I have never taken our production databases offline to do weekly maintenance as it occurs when no one is using the applciations that access the databases and all the maintenance runs without issues. I'm now being questioned why they are not all taken offline to perform the maintenance. I run the DBCCs, Rebuild Indexes, Update Statistics and all run without error (ie there are always successful and not any instance where it can't be done due to any connections), so do they NEED to be taken offline? What benefits will be gained by taking them offline?