I have a scenario wherein one user maintains a calendar of day long events. She updates this calendar frequently. One of the upper management wants her calendar to appear in his calendar automatically. Invite attendee is not acceptable, because for every entry he has to confirm the meeting. He'll also get notifications about every change. He wants the process to be silent and simply in his calendar without a lot of user overhead.
In addition, he uses his calendar for his own events and planning. This should remain unaffected.