Managing for Quality and Performance Excellence 9th Edition by James Evans,William Lindsay

Exercise 31

One of our former students who sews as a hobby observed that it's often difficult to control thread tension (tightness versus slackness of the stitch) as the tension normally exhibits variation. She learned from experience that if she adjusts the tension every time a stitch comes out too tight or loose, it generally makes matters worse. However, other times, the stitching is clearly bad and requires an adjustment. Explain how her observations relate to statistical thinking. Can you think of other situations in your life that illustrate these concepts?