CQE (CQE) 2 — Questions and Answers
Question 1: A control chart shows a run of 8 consecutive points above the centerline. This indicates:
- Normal random variation
- A process shift requiring investigation (Correct answer)
- The control limits are too wide
- Measurement system error
Correct answer: A process shift requiring investigation
Eight consecutive points on one side of the centerline is a non-random pattern signaling a process shift per Western Electric rules.
Question 2: Which sampling plan standard is most commonly referenced for attribute inspection in the United States?
- ISO 3951
- ANSI/ASQ Z1.4 (Correct answer)
- MIL-STD-1916
- ANSI/ASQ Z1.9
Correct answer: ANSI/ASQ Z1.4
ANSI/ASQ Z1.4 governs attribute (pass/fail) acceptance sampling, replacing the older MIL-STD-105E.
Question 3: The Taguchi loss function quantifies quality loss as a function of:
- Defect rate relative to competitors
- Deviation of a characteristic from its target value (Correct answer)
- Total cost of scrap and rework
- Number of customer complaints received
Correct answer: Deviation of a characteristic from its target value
Taguchi defined loss as proportional to the square of the deviation from the nominal target, L = k(y − T)².
Question 4: In a two-level full factorial design with 4 factors, how many experimental runs are required (excluding replicates)?
- 8
- 12
- 16 (Correct answer)
- 32
Correct answer: 16
A 2⁴ full factorial requires 2⁴ = 16 runs to estimate all main effects and interactions.
Question 5: Which quality cost category includes the cost of incoming inspection and receiving testing?
- Prevention costs
- Internal failure costs
- External failure costs
- Appraisal costs (Correct answer)
Correct answer: Appraisal costs
Appraisal costs cover all activities that measure, evaluate, or audit products to detect defects, including incoming inspection.
Question 6: A Pareto chart is most useful for:
- Showing the distribution of a continuous variable
- Prioritizing the vital few causes contributing most to a problem (Correct answer)
- Displaying correlation between two variables
- Tracking process performance over time
Correct answer: Prioritizing the vital few causes contributing most to a problem
A Pareto chart ranks categories by frequency or impact, applying the 80/20 rule to focus improvement effort.
Question 7: Process capability index Cpk differs from Cp in that Cpk:
- Uses three-sigma limits instead of six-sigma limits
- Accounts for process centering relative to specification limits (Correct answer)
- Is calculated only for non-normal distributions
- Requires a minimum of 100 subgroups
Correct answer: Accounts for process centering relative to specification limits
Cpk takes the minimum of (USL − μ)/3σ and (μ − LSL)/3σ, penalizing processes that are off-center.
CQE (CQE) 2
A control chart shows a run of 8 consecutive points above the centerline.
This indicates: