I was recently asked to calculate the passengers of an airport in 1 year. I used the method of what I assume would be the bottom-up approach: # of runways, utilization of runways, opening hours airport, # of planes on runway, capacity planes and utilization of planes, etc. I got pretty close to the exact number, so I assume this was a good approach :)
However, could someone please explain to me how the top-down approach would look like? Would I start with the percentage of travellers flying for leisure/work etc.? And how would I proceed then?
Thanks a lot in advance!