A toothpaste factory had a problem: they sometimes shipped empty boxes, with no tube inside. This was due to the way the production line was set up, and people with experience in designing production lines will tell you how difficult it is to have everything happen with timing so precise that every unit coming out is perfect 100% of the time. Small variations in the environment (which can’t be controlled in a cost-effective fashion) mean you must have quality assurance checks smartly distributed across the line so that customers all the way down to the supermarket don’t get mad and buy another product instead.
Understanding how important that was, the CEO of the toothpaste factory got the top people in the company together and they decided to start a new project. They hired an external engineering company to solve their empty boxes problem, as their engineering department was already too stretched to take on the extra effort.
The project followed the usual process: budget and project sponsor allocated, RFP, third-parties selected, and six months (and $8 million) later they had a fantastic solution — on time, on budget, and high quality. They solved the problem by using high-tech precision scales that would sound a bell and flash lights whenever a toothpaste box weighed less than it should. The line would stop, and someone would walk over and yank the defective box out of it, pressing another button to re-start the line.
A while later, the CEO decided to have a look at the ROI of the project: amazing results! No empty boxes shipped out of the factory after the scales were put in place. Very few customer complaints, and gaining market share. “That’s money well spent!” – he says, before looking closely at the other statistics in the report.
He was amazed to see that the number of defects picked up by the scales was 0 after three weeks of production use. It should’ve been picking up at least a dozen a day, so something must be wrong with the report. He filed a bug against it, and after some investigation, the engineers come back saying the report was absolutely correct - the scales really weren't picking up any defects, because all boxes that got to them on the conveyor belt were at proper weight.
Puzzled, the CEO walked down to the factory, and up to the part of the line where the precision scales were installed.
A few feet before the scale, there was a $20 desk fan, blowing any empty boxes off the belt and into a bin.
“Oh that,” says one of the workers — “Charlie put it there ’cause he was tired of walking over every time the bell rang”.