Sometimes a certain group of ChangeMan ZMF users (like ChangeMan ZMF admins, release managers, …) need to perform a special operation (usually planned, though sometimes unplanned). To do so, it may be that during such operations certain ChangeMan ZMF operations (e.g.: package freeze, package approve, revert to DEV, etc) cannot be used by any ChangeMan ZMF user. Shutting down ChangeMan ZMF entirely obviously is an option. But what about those situations where just shutting down the entire ChangeMan ZMF system (for a few hours or so in the middle of the day?) is not an option?