Six Sigma

The managers at Apple decided that they did not want more than 3.4 defects per one million iPhones produced. They measured it every 2 million iPhones produced. After analyzing the process, they found that the timing of machine K5S2 was .02 seconds off.  This caused Apple to have 5 defects per million.  They called in a repair man to fix the timing on that machine and to inspect the other machines to ensure that all the timings were correct.  They installed indicators that let them know if the timing was starting to get off, and they trained all machine workers in how to do minor repairs on the machines that they work on.  When they measured and analyze it again the defects were numbered at 1.05 defects per million.