C2 Quality Assurance and Improvement 2 — Questions and Answers
Question 1: Which quality improvement tool is best suited for identifying the root cause of a recurring defect by repeatedly asking 'why' until the underlying cause is found?
- Pareto chart
- 5 Whys (Correct answer)
- Control chart
- Scatter diagram
Correct answer: 5 Whys
The 5 Whys technique drills down to the root cause by iteratively asking why a problem occurred.
Question 2: A process is said to be 'in statistical control' when:
- All outputs meet customer specifications
- Only common cause variation is present (Correct answer)
- The defect rate is below 1%
- Special cause variation has been eliminated and recurs predictably
Correct answer: Only common cause variation is present
Statistical control means only natural, common cause variation exists with no special cause signals.
Question 3: A Gauge R&R study is conducted primarily to:
- Rank defects by frequency
- Assess measurement system variation (Correct answer)
- Map the steps of a process
- Identify bottlenecks in production
Correct answer: Assess measurement system variation
Gauge Repeatability and Reproducibility (R&R) quantifies how much variation comes from the measurement system itself.
Question 4: In Six Sigma, the term 'CTQ' stands for:
- Cost to Quality
- Critical to Quality (Correct answer)
- Control to Quantify
- Cycle Time Quota
Correct answer: Critical to Quality
CTQ (Critical to Quality) characteristics are measurable product or process features directly tied to customer requirements.
Question 5: Which of the following best describes a 'mistake-proofing' device in quality management?
- A checklist reviewed after production
- A device that prevents or detects errors before they become defects (Correct answer)
- A statistical chart monitoring output quality
- A training program for operators
Correct answer: A device that prevents or detects errors before they become defects
Mistake-proofing (Poka-Yoke) uses physical or procedural mechanisms to prevent errors from occurring or escaping.
Question 6: When a control chart shows a run of 8 consecutive points on one side of the center line, this indicates:
- Normal random variation
- A potential special cause requiring investigation (Correct answer)
- The process is perfectly centered
- Measurement system error only
Correct answer: A potential special cause requiring investigation
Eight consecutive points on one side of the centerline is a Western Electric rule violation signaling a likely special cause.
Question 7: The primary purpose of a Quality Management System (QMS) audit is to:
- Punish employees for non-conformances
- Verify that processes conform to planned arrangements and are effectively implemented (Correct answer)
- Replace standard operating procedures
- Reduce the number of quality staff
Correct answer: Verify that processes conform to planned arrangements and are effectively implemented
QMS audits objectively evaluate whether processes conform to requirements and are achieving intended results.
C2 Quality Assurance and Improvement 2
Which quality improvement tool is best suited for identifying the root cause of a recurring defect by repeatedly asking 'why' until the underlying cause is found?