An airline security checkpoint may be modeled as a system of two queueing networks, one for trays and the other for passengers. Let’s focus on the queue associated with the passengers. The passengers arrive at a rack of trays to hold items to be X-rayed, load the trays, and then queue to walk through a metal detector while the trays go through an X-ray machine. The network seen by the customers consists of one or more guard stations at which identities and boarding passes are checked, followed by a queue for trays, and then another queue to go through the metal detector.
Identify the type of queueing network traversed by the passengers. Explain the effect on passenger delays of having (i) multiple X-ray machines and tray racks, (ii) too few trays, and (iii) a single agent for checking boarding passes and identity documents.
Propose configurations of X-ray machines, tray pallets, and ID inspection lines when the airport has a policy of giving priority to frequent fliers at the entrance to the security area. Explain what happens if the proportion of frequent fliers at a given hour is high or low.
Sample Solution
Sample Solution
- Single queue with priority lanes. This is the most common configuration. There is a single queue for all passengers, but frequent fliers are allowed to use priority lanes that are typically shorter. This configuration is simple to implement and can be effective if the proportion of frequent fliers is high. However, if the proportion of frequent fliers is low, then the priority lanes may be underutilized.
- Separate queues for frequent fliers and non-frequent fliers. This configuration is more complex to implement, but it can be more efficient if the proportion of frequent fliers is high. This is because frequent fliers can be processed through security more quickly, which can help to reduce overall wait times.
- Dynamic queue management. This is a more advanced configuration that uses technology to dynamically adjust the number of lanes and the priority given to frequent fliers based on the current traffic conditions. This configuration can be very effective in optimizing security throughput, but it is also more complex to implement and maintain.
The impact of the proportion of frequent fliers on security throughput depends on the configuration of the security area. In a single queue with priority lanes, the impact is relatively small. However, in a separate queue configuration or a dynamic queue management configuration, the impact can be significant. If the proportion of frequent fliers is high, then the security area will be able to process more passengers per hour. However, if the proportion of frequent fliers is low, then the security area may be underutilized.
Here are some additional thoughts on the configurations of X-ray machines, tray pallets, and ID inspection lines when the airport has a policy of giving priority to frequent fliers at the entrance to the security area:
- The number of X-ray machines and tray pallets should be sufficient to handle the peak traffic load.
- The ID inspection lines should be staffed with enough personnel to ensure that passengers are processed efficiently.
- The security area should be designed to be easy to navigate and to minimize bottlenecks.
- The security area should be well-lit and clean.
- The security area should be staffed with friendly and helpful personnel.
By carefully considering these factors, airports can create a security area that is efficient, effective, and customer-friendly.
