Elevator Action

The elevator problems in Oxford's new Mathematical Institute have gotten so severe that one of the building's denizens has tried to come up with a helpful mathematical model of the problem... according to rumor, while actually stuck in the elevator...

We moved into the building at the boundary of August/September 2013. Is this really that hard to solve? I wonder what Arrowsmith would say about this problem?

(Tip of the cap to Philip Maini.)