Who’s Running at 6 Sigma?
Airplanes – Six Sigma
Airplanes run at Six Sigma. Do that mean they don’t have failures? No. But think about what you care about. The plane crashing is a failure for me. Components on planes fail all the time but who cares if the plane still flies and lands. Six Sigma is a matter of perspective. Achieving Six Sigma means 3.4 defects out of a million opportunities. Is the opportunity for an airplane a successful takeoff, flight and landing? I would say so. I wouldn’t say an opportunity is a flight mile.
How do airplanes do it? They have made an inherently and historically high risk system into an extremely safe system. They did this by separating systems on the airplane. Did you know that the electrical system on a plane can fail and the pilots can still fly the plane just fine and still land it without issue? Failure of the electrical system does not fail the flight system. So one way you can achieve Six Sigma is by measuring the “opportunity” correctly and the other is by separating systems so the failure of one does not impact the failure of another.
The FAA is proactive about issues and preventive maintenance. Your system can attain Six Sigma if it is maintained and proactively managed. If there is an issue in the fleet of airplanes (plane manufacturer and model) then this issue becomes apparent to the FAA before the airline because the FAA is looking at a larger sample size. So when they see something worrying, they issue a notice and all the planes are given the fix. So what else runs at Six Sigma?
Humans – Six Sigma
Humans, like airplanes, are a complex system. But the complexity of a human makes a plane seem simple. What is an “opportunity” for a human? Let’s say one minute. That means a human must operate correctly for two years to meet a Six Sigma requirement. Regrettably, some of us do not make two years but for the most part, we do. What makes humans so robust? One thing is continuous improvement through evolution. Of course, modern medicine helps also. Even though human’s systems are hopelessly intertwined we show extreme robustness to things that try to slow us down. Now, if we consider an “opportunity” a year, then we are not Six Sigma machines :-(.