To show how demand management and SOIA would work, I've used a particular day at SFIA. The day is August 10, 1998 which was the busiest day in 1998. There were a total of 1333 operations. The data is from the FAA Tower Records. August 10 was a good weather day. The graph below shows the number of planes arriving for each hour. Departures are not a significant problem.

Note that the actual maximum number of planes arriving in an hour was 51, well below the oft stated maximum number of 60. SFIA always implies that they need 60 planes a hour but an actual arrival rate above 55 does not occur.

In addition, the bad weather capacity with SOIA/PRM, currently being installed at SFIA, is shown. There are two lines because SFIA keeps trying to minimize the capacity with SOIA. P&D Aviation, in 1999, said the SOIA Arrival Rate would be 45 planes per hour but SFIA and the FAA want to say it's 38 planes per hour. It's probably a fuzzy number somewhere between. At any rate you can see SFIA would exceed the AAR with SOIA several times a day when there is 'bad' weather at SFIA. SOIA doesn't help on good weather days.

So now let's look at what happens with Demand Management.