October  2002

Vol. 4, No. 10

Quality Quiz

Pyncheon Shooz manages a team of inspectors for a manufacturer of extruded plastic products, primarily film cartridges for the photo industry. (He was formerly in leather product sales, but his name made it difficult to meet quotas.)
His firm, Cartridges ÔR Us, has undergone a scheduled visit from its ISO auditors, who found one major and two minor errors. The major finding, unfortunately, focused on the paucity of SPC knowledge among inspectors. Pyncheon was well aware of the deficiencies in this department. He had, after all, brought most of the inspectors from his former position, where no ISO inspection had taken place. Now he found himself in the position of instructing the inspectors, or at least teaching them enough that Cartridges ÔR Us would succeed in its next audit.
Since he could not seem to get all the inspectors together at once, he began with a group of five who were available for instruction, as long as Pyncheon promised to provide lunch for them. The other five inspectors had better offers from others in the organization who needed their attention.
Using print materials provided by the company's SPC consultant, Pyncheon went through the instruction carefully, page by page, introducing his inspectors to the meaning of attributes data. He had always assumed that it didn't make much difference which chart one used, as long as data was identified as either attributes or variables data, so when he turned the page and saw a section on u-charts, he began to mumble. It occurred to him that although he had heard of u-charts, he always thought they were called 'you-charts, ' to inspire ownership in process analysis.
To enlighten the waiting inspectors, Pyncheon finally pointed out that u-charts are really similar to X-bar and R charts, so control limits would be based on the normal distribution. He was ready to move on quickly at that point. Was his quick-witted answer correct?
A)   yes
B)   no

Copyright 2002 PQ Systems.

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