This week I attended the CREATE/TSA Symposium on Aviation Security at the University of Southern California campus. Center for Risk and Economic Analysis of Terrorism Events (CREATE) and the Transportation Security Administration (TSA).
It was a nice conference attended by academics, those at government agencies (TSA, DHS, Coast Guard, etc.), and those in the private sector. It was a good mix of attendees and speakers, and no one was shy about raising interesting and provocative ideas. Many issues were discussed in the conference from multiple viewpoints, including:
- Are we more concerned with people with a nefarious intent and no threat items or people with no bad intent but with threat items?
- How do we even begin to characterize the deterrent effect?
- Good security means making tradeoffs between efficiency, effectiveness, and cost.
- Government agencies wants more collaboration with academics. Almost all non-academic speakers mentioned this.
- What about drone security?
It was clear that aviation is still a favorite target among terrorists and that aviation security issues are still challenging. Operations research tools such as risk analysis and optimization are needed to put good ideas into action. It was nice to hear that the practitioners feel this way too. We will always have security challenges, and OR will always help us address some of these challenges.
My advisor Sheldon Jacobson talked about his work in this area, including his work with me that introduced the concept of risk-based screening (see a previous article here). Two other PhD students followed me and continued work in this area. Our work addresses on how to optimally target scarce resources at the passengers based on their risk. The models are resource allocation models that allocate screening resources to passengers statically and dynamically (in real-time). The central theme is to use limited screening resources wisely. There are inherent tradeoffs in these types of decisions: with a fixed set of resources, targeting too many resources at low-risk passengers means there are fewer resources for higher-risk passengers.
Some of the critical findings from our research include:
- We want to match passenger risk with the right amount of security resources.
- Risk based screening is great because it uses limited screening resources in an intelligent way. Random screening or screening everyone with all of the resources is not an intelligent use of resources (although some randomness can be effective when used intelligently – it just shouldn’t be the only way to use limited resources).
- When risk is underestimated, high value security resources get used on high risk passengers (a good thing). Finding a threat passenger is like finding a needle in a haystack. Underestimating risk helps you make a smaller haystack.
- When risk is overestimated, high value security resources get used on low risk passengers, which may leave fewer high value security resources available for high risk passengers. Overestimating risk prevents you from making a smaller haystack (everyone looks risky!)
- TSA PreCheck implicitly underscreens by weeding out many of the non-risky passengers to make a smaller “haystack.” PreCheck has the potential to make the air system safer in low risk, cost-constrained environments. Side note: TSA PreCheck didn’t exist when I was a PhD student working in this area, but earlier ideas and programs were out there (e.g., trusted traveler programs).
It was nice hearing from TSA practitioners who read my papers with Sheldon and used our ideas to guide changes to policy.
Sheldon will give the long version of this talk in Arlington, Virginia on August 5 at an WINFORMS meeting. Details are here.
You can also listen to my podcast interview with Sheldon about aviation security from 2011 here.
Special thanks to Dr. Ali Abbas (CREATE director), Kenneth Fletcher (TSA), and Jerry Booker (TSA) for organizing the conference and to Stephen Gee, Lori Beltran, and Michael Navarrete for their hard work organizing the conference. Ali promised to write an OR/MS Today article about the symposium, so stay tuned for more details.