Which statement about Cp/Cpk vs design capability is correct?

Which statement about Cp/Cpk vs design capability is correct?

• A. Cp/Cpk measures product aesthetics.
• B. Cp/Cpk assesses manufacturing ability; design capability relates to tolerances and reliability.
• C. Design capability has nothing to do with tolerances.
• D. Cp/Cpk is used for shipping schedules.

Answer: (B)

Cp and Cpk quantify how well a manufacturing process can produce parts within the specified tolerances. Cp looks at the potential capability based on the spread of the process, while Cpk accounts for the actual centering of the process relative to the tolerance limits, giving a true picture of production performance. This makes them manufacturing capability indices, not measures of aesthetics or shipping schedules. Design capability is about whether the tolerances set in the product design are realistic and will yield reliable performance, considering design requirements and expected variation. So, Cp/Cpk assess manufacturing ability, and design capability relates to tolerances and reliability.

Cp and Cpk quantify how well a manufacturing process can produce parts within the specified tolerances. Cp looks at the potential capability based on the spread of the process, while Cpk accounts for the actual centering of the process relative to the tolerance limits, giving a true picture of production performance. This makes them manufacturing capability indices, not measures of aesthetics or shipping schedules. Design capability is about whether the tolerances set in the product design are realistic and will yield reliable performance, considering design requirements and expected variation. So, Cp/Cpk assess manufacturing ability, and design capability relates to tolerances and reliability.