CHAPTER 7 CHAPTER 7 Baggage Handling
7.7 Management and Performance Metrics
Well-defined performance metrics are an important part of the management of baggage- handling processes and systems. There are measures of the overall end-to-end performance of the baggage process, as well as subsidiary measures that focus on particular elements within the end-to-end process.
Overall
The industry-standard measure of success is the short-landed rate. This is the number of bags reported missing at the destination per 1,000 passengers flown—the lower this ratio, the better is the performance of the end-to-end baggage process. This ratio varies by airline, but is typically on the order of 1/1,000 for direct bags.
The short-landed rate for transfer bags is higher than for direct bags. This varies greatly by airline, route, and other factors, but typically is on the order of 5 to 50/1,000. This reflects the fact that a transfer bag is at greater risk of missing its connecting flight than one that is checked in directly. The reason for this is that the inbound leg of a transfer bag’s journey is more variable. Factors include
• Late inbound aircraft, leading to little or no time to make the connection
• Poor segregation and loading of time-critical bags on inbound aircraft
• Poor handler performance in unloading and delivering bags to the baggage system
• Poor bag tag quality, leading to the need to manually code the bag
• Lack of data from the inbound airline, leading to the inability to sort the bag to the correct makeup position
At a hub airport, the overall short-landed rate is dominated by the transfer short-landed rate. For example, if the transfer ratio (the fraction of transfer passengers to the total of all passengers) at an airport is 50 percent, the direct short-landed rate is 1/1,000, the transfer short-landed rate is 40/1,000, then the overall rate is 20.5/1,000. Even if the direct rate were reduced to 0/1,000, the overall rate still would be 20/1,000. This explains why baggage performance-improvement programs at hub airports have to focus on the transfer- baggage product. It also shows that when comparing the baggage performance of different airports, it is vital to understand each airport’s transfer ratio.
When comparing transfer short-landed rates between airports, it is important to bear in mind that different airports can and do offer different minimum connection times. Thus, a performance of 20/1,000 with a minimum connection time of 45 minutes will involve much better processes, systems, and operations than the “same” performance of 20/1,000 with a minimum connection time of 75 minutes.
This illustrates that there is a tradeoff between shorter minimum connection times and lower short-landed rates. Indeed, at one point, Emirates, for a while, chose to increase its
In other markets, though, there is perceived to be a competitive advantage to offering lower minimum connection times, resulting in a challenge to manage short-landed rates within tolerable levels.
Baggage System
Under normal circumstances, baggage-handling systems contribute only a very small fraction to the overall short-landed rate. The system-related measure is the system- attributable mishandled-bag rate. This is the number of bags that are mishandled by the system (e.g., delivered late or to the wrong output) per 1,000 bags handled by the system.
Values depend on the complexity and extent of the system but typically are on the order of 0.1/1,000—in other words, an order of magnitude smaller than the direct short-landed rate.
The time it takes a bag to be processed through a baggage system can be important.
For a small, simple direct system, the time from checkin to output may be only a few minutes and so is only a minor element of the end-to-end process. In contrast, a large baggage system with distributed inputs and outputs across several terminal and concourse buildings typically will have an in-system time of 10 to 20 minutes depending on its scale and the processing required. Such times become a significant part of a minimum checkin time of, say, 30 minutes before departure or a minimum connection time of, say, 45 minutes and therefore need to be monitored.
For systems that have no integrated bag storage, a simple measure of in-system time is likely to be sufficient to monitor system performance, although this has to be coupled with a measure of availability of sufficient input capacity, whether at checkin or at transfer inputs.
For systems that do have storage and buffering (and especially systems that make use of some form of the batch-building concept), an in-system time is of little relevance for the majority of bags that enter the system with plenty of time to go. They are simply held within the system until such time as they are ready to be delivered and made up. Nevertheless, in-system times remain vital for time-critical bags and should be monitored.
Arrivals Delivery Performance
The speed of delivery of bags from an inbound aircraft to either a reclaim device (for terminating bags) or the input of the baggage-handling system (for transfer bags) is the key measure of handler performance. Historically, this has been measured by first and last bag delivery times—for example, first bag on reclaim within 15 minutes and last bag on reclaim within 25 minutes of aircraft arrival on chocks. Such measures have the benefit of simplicity and can be used to encourage good handler performance, but three trends mean that more refined targets are becoming necessary at some airports:
• An increase in the number of very large aircraft
• A desire to reduce minimum connection times
• An increase in the size of airports and hence distances between facilities
The implications of these trends are described in turn. First, a performance standard based on delivering, say, 250 bags from a mediumsized aircraft becomes challenging to achieve for a very large aircraft with 500 or more bags. Second, the need to achieve
reliable, short-transfer connection times (especially from very large aircraft with many transfer bags) means that a tighter performance standard needs to be applied to the time- critical transfer bags while allowing more time for non-time-critical bags. Third, large airports (without distributed arrival baggage systems) inevitably lead to longer driving times from some stands to reclaims than from others, making a “one size fits all” standard inappropriate.
In order to deal with the growth in size and scale, different priorities can be assigned to the four main categories of inbound bags:
• Premium terminating (e.g., first class, business class, frequent-flyer cardholders)
• Economy terminating
• Short-connect transfers (with scheduled connection times of less than about 2 hours)
• Long-connect transfers (with scheduled connection times of more than about 2 hours)
Logic dictates that premium bags should be delivered before economy bags and that short-connect bags should be delivered before long-connect bags. The only remaining choice is whether to prioritize premium bags over short-connect bags or vice versa. Long- connect bags should be given the lowest priority in any case. Of course, the ability to fine- tune the delivery of these different categories depends on the appropriate segregation and loading of the inbound aircraft.
For reclaim, it is desirable to set targets for the delivery of bags relative to the arrival of passengers in the reclaim hall. For example, the aim might be to deliver all premium bags before the first passengers reach the reclaim hall so that no premium passengers have to wait for their bags. A maximum-waiting-time target might be set for economy passengers.
In practice, this can be hard to measure and control. While processes and systems can be put in place to log when a bag is delivered to the reclaim device, it is much harder to monitor the arrival times at reclaim of specific passengers. Another difficulty is the spread in passenger processes from disembarkation to arrival in the reclaim hall. A small aircraft, parked at the main terminal building with domestic passengers who do not need to clear immigration, can mean passengers reaching the reclaim hall within a few minutes of arrival on stand. In contrast, a large aircraft, parked remotely, with many international passengers requiring complex immigration and/or customs checks, can mean passengers taking an hour or more to reach the reclaim hall.
This illustrates rather clearly that passengers’ perceptions of the performance of the baggage-reclaim function are influenced not so much by the absolute time it takes for bags to be delivered but by whether or not their bags are waiting for them—a long immigration process can make a mediocre baggage-delivery performance appear to be very good.
References
International Air Transport Association (IATA). 2004. Airport Development Reference Manual, 9th ed. Geneva:
IATA.
Transportation Security Administration (TSA). 2011. Planning Guidelines and Design Standards for Checked Baggage Inspection Systems. Washington, DC: TSA.