I found this anecdote today in the December 2007 issue of "Power" magazine:When searching for the cause of a failure, we often overlook the obvious. This is especially true for formally educated technologists—we relish the thought of digging into nitty-gritty details and exploring all kinds of complex possibilities. But what we should be doing is purposely introducing ignorance—asking the simple questions first. One failure specialist (I love that job title!) tells this story:
I accompanied a fellow worker to one of our sulfuric acid plants to help rebuild one of its waste-heat boilers. Barney was much more experienced than I was, and had been coming to the site annually for a long time—these waste-heat boilers had been rebuilt once a year for the last 20 years because of sulfuric acid corrosion. I respected Barney greatly, as did all site personnel.
The next morning, we met with an equally respected team of corporate metallurgists who had also been coming to the site annually, as well as the plant’s reliability engineering staff. I learned that once per year, these experts would get together to try to get more life out of the boiler tubes. They had tried just about every metal they could think of.
I looked around the room and noted that while individual members of the group had changed from time to time, the collective team of experts had inherited all the folklore and tradition from their predecessors. Their biases were obvious to me, so I started asking some simple, straightforward questions. They answered my questions politely, but they were clearly annoyed.
That night, I came right out with it and asked Barney, “What causes the boiler tubes to corrode?” He flashed me a disgusted look and said, “This is a sulfuric acid plant. Acid is made in the boilers. Boiler tubes and sulfuric acid don’t mix well. So don’t ask such a stupid question.”
The next morning, we met with the plant manager. Still troubled, I blurted out, “I just don’t understand why anyone would design a boiler with tubes that will corrode in one year!” Barney could have shot me. But the plant manager was wide-eyed. “You know,” he said, “I’ve been wondering the same thing, but I didn’t want to sound stupid. Our other sulfuric acid plant isn’t having these problems. Sure, we begin the acid-making process in the boilers, but there’s not supposed to be acid until after those tubes.”
Encouraged by this exchange, I called my boss at the home office and suggested that we conduct a full-blown root-cause analysis. He liked the idea so much he flew to the plant site to personally propose the project. When he was explaining the proposal, my boss said that “only the truly ignorant can ask the questions that lead to discovery because they don’t know enough to be ashamed of themselves.” Then, he looked at me and said, “We’ve got one of the most ignorant people imaginable right here!”
The proposal was accepted, and the study pinpointed as the cause of failure a dew point problem, not a metallurgical one. When we verified our hypotheses, we moved the affected tubes one foot behind their original location. It worked! In fact, we eventually changed the tube materials back to their original, less-expensive specification.
The team of experts had looked at this problem for 20 years! They were brilliant in their field, but they made two of the most common mistakes in problem-solving. First, they tried to solve the problem before they looked at the evidence (some have described this as a medical problem called “premature evaluation”). Second, they failed to introduce ignorance. To help break what often can be a thin shell of understanding, you must intentionally pit ignorance against expertise.
I find it so hard to ask the stupid question. When my son was in high school he was even in a class where anyone who asked what the rest of the boys considered a blatantly stupid question had to put a quarter in the pizza fund. I hope there were no sensitive people in the class, but your average teenage boy thought it was great fun. Even without paying a fine, we all wanted to have the right answer or the insightful question. We need to reward people who do ask the dumb question, not roll our eyes. Besides, we probably didn't know the answer either.
[Hey - have you tried using Google notebook? It was great for saving this little story and finding it later - it even links to the source page. An icon stays in the corner of your browser so you can open it quickly, then close it up. And you can park it on your iGoogle home page. I'm getting to be all Google, all of the time.]