CQE (CQE) Course 5 — Questions and Answers
Question 1: In Six Sigma, the DMAIC roadmap is applied to:
- Design new products from scratch
- Improve existing processes by reducing defects (Correct answer)
- Develop supplier qualification criteria
- Establish calibration intervals for instruments
Correct answer: Improve existing processes by reducing defects
DMAIC (Define, Measure, Analyze, Improve, Control) is a data-driven methodology for improving existing processes and reducing defect rates.
Question 2: Which hypothesis test is appropriate for comparing the means of two independent groups when population variances are unknown and assumed unequal?
- Paired t-test
- One-sample z-test
- Welch's t-test (Correct answer)
- Chi-square test
Correct answer: Welch's t-test
Welch's t-test (unequal variance t-test) compares two independent group means without assuming equal variances.
Question 3: A Pareto chart helps a quality engineer to:
- Monitor process stability over time
- Identify the vital few causes that account for most of the problems (Correct answer)
- Determine if two variables are correlated
- Compare before-and-after improvement results
Correct answer: Identify the vital few causes that account for most of the problems
A Pareto chart ranks defect categories by frequency and cumulative percentage, revealing the 'vital few' causes that drive the majority of problems.
Question 4: When a control chart shows a run of 8 consecutive points on the same side of the centerline, this indicates:
- Common cause variation only
- A special cause that should be investigated (Correct answer)
- The process is perfectly centered
- The control limits need to be recalculated
Correct answer: A special cause that should be investigated
A run of 8 or more consecutive points on one side of the centerline is a non-random pattern that signals a special (assignable) cause.
Question 5: Which element is NOT typically included in a Quality Management System (QMS) document hierarchy?
- Quality policy
- Quality manual
- Work instructions
- Marketing strategy (Correct answer)
Correct answer: Marketing strategy
A QMS document hierarchy consists of the quality policy, quality manual, procedures, and work instructions; marketing strategy is a business document outside the QMS scope.
Question 6: In reliability testing, an accelerated life test is used to:
- Shorten test duration by applying elevated stress conditions (Correct answer)
- Simulate normal operating conditions exactly
- Verify compliance with regulatory standards
- Establish process control limits
Correct answer: Shorten test duration by applying elevated stress conditions
Accelerated life testing applies higher stress levels (temperature, voltage, vibration) to compress product lifetime into a shorter test window and predict field reliability.
Question 7: A corrective action system is most effective when it includes which of the following as a final step?
- Identifying the problem
- Implementing a containment action
- Verifying that the corrective action prevented recurrence (Correct answer)
- Assigning responsibility to a team member
Correct answer: Verifying that the corrective action prevented recurrence
Verification of effectiveness confirms that the root cause was eliminated and the problem has not recurred, closing the corrective action loop.
CQE (CQE) Course 5
In Six Sigma, the DMAIC roadmap is applied to: