If the C_pk index exceeds 1: A) the AQL must be smaller than the LTPD. B) σ must be less than one-third of the absolute value of the difference between each specification limit and the process mean. C) the x-bar chart must indicate that the process is in control. D) the process is capable of Six Sigma quality. E) the process is characterized as "not capable."

Question

Quizplus · Accepted Answer

When the C_pk index exceeds 1, it indicates that the process is not capable of meeting the specification limits. In such cases, the process capability ratio (Cpk) must be calculated, with a value of at least 1.33 indicating Six Sigma quality. However, as for the given options, the only valid choice is B, as it suggests that the process variation should be less than one-third of the specification width to achieve an acceptable process performance. A lower variation will result in a higher Cpk value, enabling the process to fulfill the customer requirements. Choices A, C, D, and E are incorrect as they do not provide relevant criteria to judge the process capability based on the C_pk index.

If the Cpk Index Exceeds 1

If the C_pk Index Exceeds 1