First I would like to understand what do we mean by throughput. It can mean # of planes departed or arrived or both. It can also mean # of people departed or arrived or both. I will assume that here Throughput means # of people departed from the airport.
Second, I would like to understand where is the bottleneck because that is the reason we cannot increase our throughput today. After I find the bottleneck, I will come up with solutions to eliminate the bottleneck and increase the throughout.
Third, I will measure the increase in throughput and if it is less than 100% increase, I will find the new bottleneck in the process and eliminate it. I will continue this process until we increase throughput by 100%.
To find the bottleneck, I would ask questions and gather data. One scenario could be that the bottleneck exists outside the airport i.e. airport can handle 100% increase in throughput but people are not booking the flight because
1. They do not see our airport on the travel booking website like expedia, kayak
2. The flights they see through our airport are more expensive that other nearby airports
3. Major airlines do not fly from our airport
4. There is another airport closer to city and our airport is very inconvenient to reach
5. Our website is broken
I have listed solutions to above situations below but the actual solution can only be designed after we get the data and extract the problem
1. Identify why we are not part of list. If listing involves paying a fee, evaluate the how much benefit (e.g. traffic we will get) w.r.t. to the cost and take the decision. Paying the fee is not always a good decision e.g. Southwest can only be booked from its website
2. Find out the reason. If there is an added benefit like better airlines, communicate it to public but if same airline charges more for same flight from our airport vs a nearby airport, discuss with the airline.
3. Talk to the airlines and understand why they are not flying through our airport. May be we need to create more gates or reduce fee.
4. Free shuttle service or a train connection from city to our airport. Another option could be to partner with the other airport closer to city and connect the 2 airports with shuttle/train. This will increase attractiveness of both airports for airlines since now we operate as a bigger entity and can attract more traffic. We can now negotiate price with airlines (think of “supplier power” in 5 Forces framework)
5. Find out where it is broken and fix the website.
Second scenario could be our security clearance take a long time and people have to come 3 hours early. This is often a problem with big airports and sometimes a reason that people prefer to fly from smaller airport that has relatively less traffic.
More scenarios: cleanliness, no options for food, not enough parking, cabs are expensive to reach airport as direct road is broken and they have to take a long detour, an accident happened that damaged our reputation.
In summary, I will understand what throughput means, identify where is bottleneck by coming up with multiple scenarios, then go deeper in that scenario to understand actual problem and find the solution. If increase in throughput is not 100%, I will find the new bottleneck, actual problem, solution.