Capability statistics are wonderful things. They tell you how well your process is meeting the specifications that you have. But there are so many capability statistics that it’s worth taking some time to understand how they’re useful together.

Recently, a friend from my undergraduate days complained that he was written up at work for low productivity. He operates a forklift in a warehouse and was informed that he only reached 97 percent of the previous week’s productivity.

What do you see when you look at the image in figure 1? Do you see a bulging sphere that stretches the checkerboard pattern in the center, causing its lines to curve?

Last week marked the 100th anniversary of the introduction of a moving assembly line at Henry Ford’s Highland assembly plant, an innovation that inaugurated mass production.