SPC Process Variation & Capability

Question 1

What is the primary source of common cause variation?

Accepted Answer

Normal process variability

Answer

Common cause variation is inherent to the process and results from normal, random factors.

Question 2

What does a Cp value greater than 1.33 typically indicate?

Accepted Answer

High process capability

Answer

A Cp value above 1.33 suggests the process is capable of meeting specifications with minimal variation.

Question 3

Which tool is used to determine the spread and centering of a process?

Accepted Answer

Capability histogram

Answer

A capability histogram displays the process spread relative to specification limits, showing capability and centering.

Question 4

What does Cpk take into account that Cp does not?

Accepted Answer

Process centering

Answer

Cpk measures process capability while considering how centered the process is between the specification limits.

Question 5

Which term describes a process that consistently produces within specification limits?

Accepted Answer

Capable

Answer

A capable process produces outputs within specification limits, reflecting good performance and low variation.

(SPC) Statistical Process Control Certification Practice Test