Quality quiz (December 2017)—and November’s quiz winners!

Winners of last month’s quiz and a copy of Practical Tools for Continuous Improvement: Volume 1 are Shavon Barnett (Environmental Dynamics International of Columbia, MO); Chad Savitz (Grand Valley Manufacturing Co. of Titusville, PA); and James Stevens (Ulterra Drilling Technologies of Ft. Worth, TX). For this month’s quiz, and a chance to win a copy of Practical Tools for Continuous Improvement: Volume 1, submit your response by December 31.

Marge Orrine, quality manager of Natural Dairy Products (“Our moos deliver good news”), is intent on being the first woman in her organization to achieve Black Belt status. She has given a great deal of thought to identifying a project that will save her company millions, so that she will be assured of getting the attention she needs for a Black Belt.

Over a period of several months, Marge has noticed the number of defective packages of butter that emerge from one of the packaging lines in the plant. Each stick seems to have a different weight. One source of the problem may be that the butter is being wrapped before it is cold enough to hold its shape through the packaging process, causing the weight to vary. Whatever the source of the problem, it is costing NDP a great deal through excessive waste.

Marge Orrine decides to collect data about the inconsistent sticks of butter, and uses a specialized scale to weigh each stick as it emerges from the packaging line. She samples five sticks each day for 10 days:

When Marge’s boss notices the intense measuring activity on the packaging line, he asks her what she is doing. She smiles knowingly and says that she is calculating the average weight of the sticks of butter. Using a nearby white board, she demonstrates the formula that she is using for this calculation:

Impressed because he has only limited understanding of statistics himself, Marge’s boss asks about the difference between the mean and the median. Marge, being clueless about the distinction, does not to sully the status she has achieved by her demonstration of the formula. “Median is about half of the mean,” she says confidently.

Is Marge’s response within the realm of reality?