Click here for Quality Quiz Video Explanation
Allie Katt, recently appointed as a quality technician
at Natural Dairy Company, has been charged with creating a control
chart for the cottage cheese production line. Each day, the plant
produces the number of containers that has been ordered the day
before. These orders range from 400 to 2,300 per day.
The final setp on the prodution line is a check for Ph values by
an inspector, who removes cartons that fail his test. Allie has
just learned charting techniques, and determines--based on what
she remembers about control charts--that this process demands the
use of a p-chart, a chart that measures the percentage of rejects
or defects. Fortunately, she has a copy of SQCpack to create
the following chart:
"Aha!" she exclaims when she inspects
the chart. Spotting a point outside the upper control limits, she
notes, "Out of control on February 2 (sample 10) and February
17 (sample 21)," and shuts the line down to address the offending
process. Smug in the demonstration of her ability to read the chart,
she forms a team to disassemble the fill machine to identify the
A visiting consultant, Awana Gohome, happens to
be in the plant that day, and stops to examine the chart that Allie
has been studying. Noting that the number of cartons inspected in
each sample varies by a large margin, Awana states in her firm consultant
voice that the chart is invalid.
Is Awana right?
a) Yes. The process
cannot be assessed accurately under these circumstances.
b) No. Awana Gohome
is just a nitpicking consultant. She should go gome.
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