Rand: Boeing's strong airport security model suffers from imprecise inputs

Tools

Boeing has developed a strong model for the Transportation Security Administration to test the effectiveness of its airport security efforts, but the information input into it is sometimes weak, the Rand Corp. says in a new report (.pdf).

The tool models the interactions between security systems and those who seek to attack commercial airplanes. TSA has used it to estimate the benefits of full-body scanners and behavior-detection officers, the report says. The tool factors in estimates of terrorists' abilities and decision processes, then models how the layers of airport security would fare against dozens of different types of attacks.

TSA asked Rand to assess the tool before it relies on it for high-stakes decisions. Rand says it captures the key security features in place at airports, and is also simple to adjust to incorporate real-world changes. With good information, the report says, the model could credibly estimate the chances that a terrorist attempt would be stopped.

But its information has many limitations. For example, the tool discounts the value terrorists place on psychological and symbolic effects of attacks, the report says.

It also includes many variables that can't be precisely estimated, such as terrorists' perception of diminishing returns in coordinated attacks, or how quickly a terrorist can take in new knowledge of security systems.

About 200 of the tool's input values can be estimated incorrectly, the report says.

Even with the best available information, "the presence of deep uncertainties make such best estimates poor ones on which to base policy decisions," the report says.

When some inputs aren't precisely knowable, a risk model has to use a range of plausible values, which can lead to a large set of outcomes "that would strain analysts' efforts to make sense of," it says.

For more:
- download the report, "Modeling Terrorism Risk to the Air Transportation System An Independent Assessment of TSA's Risk Management Analysis Tool and Associated Methods" (.pdf)

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