Which of the following statements is NOT correct?
A) Control limits represent the "voice of the process."
B) The average of the measurement data collected is the same as the center line.
C) Six sigma equates to 99.74% of output within the control limits.
D) A normal distribution of a process under control will include a very small amount outside the control limits.

Question

Quizplus · Accepted Answer

Traditional quality control establishes control limits plus/minus 3 std. dev. which equates to 99.74%. Six sigma is a much more stringent standard at a defect level of only 3.4 parts per million production opportunities.

Which of the Following Statements Is NOT Correct