Twice a year I teach a day on design of experiments (DOE) at Ohio State University’s Fisher College of Business. The students are top-flight executives seeking six sigma black belt certification. To demonstrate their proficiency for doing DOE, I ask them to break into teams of three or four and, within a two hour period, complete a two-level factorial on paper helicopters.*
It’s always interesting to see how intensely these teams from industry compete to develop the ‘copter that flies longest while landing most accurately. However, this year one group stood out as being less competitive than the others. Therefore, I was very surprised that they handily won our final fly-off. It turns out that one of their factors was dropping the helicopter either wings-up or wings-down – the latter configuration being completely non-intuitive. It turns out that going upside down makes it easier to drop, the flight time suffers only slightly and the flight becomes far more accurate – a premium in my overall scoring.
“The chief enemy of creativity is ‘good’ sense.”
– Pablo Picasso
Ironically, another team who benefited from having an expert in aeronautical engineering and a very impressive work ethic all around – they did more runs by far than anyone else – never thought of flying the ‘copters upside down. In fact, their team leader objected very vigorously that this orientation must not be allowed, it being clearly unfair. Fortunately, other executives in this black-belt class hooted this down.
I thought this provided a good lesson for process and product improvement – never assume that something cannot work when it can be easily tested. That’s the beauty of DOE – it enables one to screen unknown (and summarily dismissed) factors to uncover a vital few that often prove to be the key for beating the competition.
*I also do this experiment for a class on DOE that I teach every Spring at South Dakota School of Mines and Technology. In fact, I am writing this blog from their campus in Rapid City where I’ll be teaching class tonight. For details, pictures and results of prior experiments here and at OSU, see this 2004 Stat-Teaser article on “Playing with Paper Helicopters”.