Statistics Quality Control & Assurance 3

Question 1

Process capability index Cpk differs from Cp in that Cpk:

Accepted Answer

Accounts for process centering relative to specification limits

Answer

Cpk adjusts for how well-centered the process mean is between the specification limits, while Cp assumes the process is perfectly centered.

Question 2

In Six Sigma terminology, a process operating at 6-sigma quality level produces approximately how many defects per million opportunities (DPMO)?

Accepted Answer

3.4

Answer

A Six Sigma process produces approximately 3.4 DPMO, accounting for the standard 1.5-sigma long-term shift in the process mean.

Question 3

Which DMAIC phase involves identifying the root cause of a quality problem?

Accepted Answer

Analyze

Answer

The Analyze phase uses tools like fishbone diagrams, hypothesis testing, and regression to identify root causes of defects or variation.

Question 4

A quality engineer uses an Operating Characteristic (OC) curve. The y-axis of this curve represents:

Accepted Answer

The probability of accepting the lot

Answer

The OC curve plots the probability of lot acceptance (y-axis) against the true lot fraction defective (x-axis) for a given sampling plan.

Question 5

Total Quality Management (TQM) emphasizes which of the following as the primary driver of quality improvement?

Accepted Answer

Customer focus and continuous improvement involving all employees

Answer

TQM is a management philosophy centered on customer satisfaction and continuous improvement (kaizen) through organization-wide participation.

Statistics Practice Test