Question 1
Which of the following is true regarding the process capability index C
pk?
◦ A C
pk index value of 1 is ideal, meaning all units meet specifications.
◦ The smaller the C
pk, the more units meet specifications.
◦ The larger the C
pk, the more units meet specifications.
◦ Positive values of the C
pk index are good; negative values are bad.
◦ The C
pk index can only be used when the process centerline is also the specification centerline.
Question 2
If the C
pk index exceeds 1
◦ the x-bar chart must indicate that the process is in control.
◦ σ must be less than one-third of the absolute value of the difference between each specification and the process mean.
◦ the process is capable of Six Sigma quality.
◦ the process is characterized as "not capable."
◦ the AQL must be smaller than the LTPD.