A toothpaste company had a small rate of faults when producing the product, every couple of thousand tubes produces the machine would put an empty one on the production line, it would then be packaged and shipped, so every now and then a customer would complain he bought an empty toothpaste.
The company decided to fix that, hired a couple of consultants, and after a dozen of engineers looked into the problem for a couple of months and burned a couple of millions in research they came up with a brilliant solution.
before packaging the toothpaste, they added a very sensitive balance to the production line, every toothpaste would pass there, if the balance detected a difference in the expected wight it would pause the line, then a mechanical arm would push it out, go back to the resting place and continue the line.
After implementing the solution the managers waited a couple of months to see the results and compare numbers, to see how efficient the new solution was. It was amazing! 100%. not one complaint of empty tubes after the expensive solution was implemented. The board was so satisfied with the investment that they came to the production floor for a tour on the new QA perfect tool. But it was turned off. They called the floor manager and asked what happened, they couldn't turn off that important piece of the production line, they could have all the complaints back. The floor manager said he doesn't even remember how to turn it on, he said, I turned it off shortly after the put this thing here.
So how it is possible they have 0 complaints with if not because of the new tool? The floor manager said it was slowing down production, every now and then it would completely stop the whole production line, so he turned it off and bought a fan, pointed out to the stop, the fan would be string enough to push any empty toothpaste case.