US Homeland Security and Six Sigma

TSA body scanner

Dallas Morning News reported a study conducted by the Oxford Economics on March 2, 2010 about the Lost Decade of the Travel Industry:

A study for the U.S. Travel Association estimates we lost $509 billion in travel exports between 2000 and 2009. In a decade where the nation’s trade deficit was more than $5.5 trillion, we lost a chance to reduce the deficit by $270 billion just from international travel. The study by Oxford Economics found the number of international travelers was up nearly 200 percent worldwide in the last decade but fell 9 percent for the United States.

The study shows that money was left on the table and US missed the opportunity to collect them to reduce its deficit. The study does not include the cost of adding those security personnels and equipments after 9-11. In this blog, I would like to point out a common misunderstanding of quality control by using the news article as an example of the Six Sigma, namely, the choice between strengthening the overall security versus solving the root cause of a security problem.

If we treat the homeland security as a six sigma problem and assume the defects are the terrorist acts to the US, the lost in travel revenue and the security cost combined become the cost of quality control (QC), namely, the cost of catching defects, if they are not detected in the first place. The referenced article shows that combined cost is huge and represents a huge spending of tax payers’ money.

In Six Sigma, the cost of quality control increases dramatically, when the control is placed away from the root cause of the defects.

Funnel View of Quality Control Cost

Funnel View of Quality Control Cost

Six sigma emphasizes the prevention of defects in the first place instead of spending money on quality control. Quality control is never the best place to stop the defects.

Taking the 2009 Christmas bomber as an example, the root cause of the incident was the failed communication in US intelligence agencies and the failure of the visa black list. Instead of (or in addition to) fixing the root cause, the recommendation was to add many expensive body scanners at airports to stop bombers from entering the US. If the intelligence were fully analyzed and the visa black list were carefully determined, there would be little need to add those body scanners. A great deal of money would be saved. Personal privacy would be preserved. And, international travel would be much convenient.

The addition of body scanners may strengthen the “overall” security but the cost and social impact are too great to ignore.

This example shows a common mis-conception of quality by emphasizing too much on quality control. Adding inspection in the first place without addressing the root cause simply adding cost. This action has a short-term effect to prevent defects. However, it is never a long-term fix to defects; it is just a patch to the quality issue. To stop the defects permanently is to never let them happen! This is the spirit of six sigma.


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