Applying simulation in a consulting environment - tips from airport planners

This paper describes the typical steps performed in a simulation consulting project in the aviation industry. While the aviation consulting environment does require some differences in the specific approach, the general framework has been applied successfully in the more traditional areas of logistics and manufacturing. 1 SIMULATION IN AIRPORT DESIGN Airport design is, by far, the largest practice area for TransSolutions. This is a unique area, with many differences from typical simulation in manufacturing or logistics. Passengers and bags arrive at the airport by the planeload. At the busiest airports the arrivals and departures are coordinated, so that several flights arrive within a short time. Then, after a short time on the ground the aircraft all depart again. A large number of passengers move through the facility during the peak period between the flight arrivals and the departures. After that, the facility will be empty until the next bank of arriving flights. The terminal facilities must be sized to handle these waves of passengers throughout the day. Space within the terminal building is at a premium. Most travelers are aware of the ticket counters, gate lounges, corridors and shops in the public areas. Hidden behind the scenes are the various offices, control rooms, and break areas for the airport and airline employees. The baggage system and various maintenance functions take up most of the space on the ramp level below the passenger areas. The usual question asked by the architects is: “will the facility, as designed, satisfy the needs of the tenant airlines?” This involves comparing the “performance” of the facility to minimum acceptable standards. A typical example is that all passengers connecting from an arriving flight to a departing flight must be able to reach their departure gate within 30 minutes of arrival. Another 67 example it that all baggage must be delivered to the claim area within 20 minutes of the flight arrival. There may be many other performance requirements, depending on the size and scope of the project. We will briefly describe some of the basic areas within the airport environment where simulation can be readily applied. The aviation environment is rich with areas where simulation or other stochastic methods can be applied. Some of the major applications of simulation in the airport environment are summarized in the following sections. 1.1 Airspace/Airfield Capacity The US Domestic Airspace can be thought of as a large link and node network. Aircraft are required to maintain separation between other aircraft. As aircraft approach an airport they are funneled closer together – with many routes converging into common links. Simulation is useful to evaluate the capacity of the link node network and to evaluate alternative link node structures that could improve capacity. Additionally, ground movements of aircraft represent another link node network. Arriving aircraft move from runways to taxiways to taxi-lanes and eventually to their gates. Aircraft may need to hold on the airfield before reaching to their gate due to general ramp congestion or due to gate unavailability. Departing aircraft follow the reverse process and also usually wait in a departure queue before accessing the runway for take-off. The movement of the aircraft must be carefully planned since many taxi-lanes and taxiways are bidirectional and can only accommodate aircraft movement in one direction at a time. Additionally, aircraft need to be able to stop or park at designated areas on the airfield so that they do not impede the movements of other aircraft. Simulation is frequently used in airfield analyses to determine the benefit (capacity improvements or delay reduction) of adding new runways, taxi-ways, and taxilanes, as well as evaluating how alternative gate allocation strategies impact airfield capacity.