CQIA Quality Tools & Techniques for Problem Solving 3 — Questions and Answers
Question 1: A histogram shows data that is skewed to the right. This most likely indicates:
- The process is centered on the target
- There is a natural lower limit preventing values from going below a threshold (Correct answer)
- The process has too many defects on the upper side
- The data was collected incorrectly
Correct answer: There is a natural lower limit preventing values from going below a threshold
Right-skewed data often results from a natural lower boundary (like zero), which clusters data on the left and stretches the tail to the right.
Question 2: Which of the following BEST describes the purpose of a control chart's upper and lower control limits?
- They define the customer's specification requirements
- They identify the boundaries of common cause variation (Correct answer)
- They set goals for process improvement
- They separate high-quality from low-quality output
Correct answer: They identify the boundaries of common cause variation
Control limits are statistically calculated boundaries representing the expected range of common cause variation in a stable process.
Question 3: An affinity diagram is MOST useful when a team needs to:
- Track defect frequency over time
- Organize a large volume of ideas into natural groupings (Correct answer)
- Determine root cause of a single defect
- Measure process capability
Correct answer: Organize a large volume of ideas into natural groupings
An affinity diagram organizes large amounts of qualitative data or ideas into logical groupings based on natural relationships.
Question 4: In the Plan-Do-Check-Act (PDCA) cycle, what activity occurs during the 'Check' phase?
- Implementing the solution on a small scale
- Standardizing the successful changes
- Evaluating results of the implemented plan against expected outcomes (Correct answer)
- Identifying the problem and planning a solution
Correct answer: Evaluating results of the implemented plan against expected outcomes
The Check phase involves comparing actual results to expected outcomes to determine whether the plan achieved its goals.
Question 5: A team discovers that 3 of 15 defect categories account for 78% of all defects. This finding is BEST visualized using a:
- Run chart
- Scatter diagram
- Pareto chart (Correct answer)
- Box plot
Correct answer: Pareto chart
A Pareto chart displays defect categories in descending order of frequency with a cumulative percentage line, making it easy to see which few categories dominate.
Question 6: Which quality tool would help a team visually display how sub-processes and sub-causes relate to the main causes in a complex problem?
- Check sheet
- Pareto chart
- Tree diagram (Correct answer)
- Scatter diagram
Correct answer: Tree diagram
A tree diagram systematically breaks down a main topic into sub-topics and details, showing hierarchical relationships between causes or tasks.
Question 7: When plotting data on a scatter diagram, which outcome best supports considering a cause-and-effect relationship?
- Data points scattered randomly with no pattern
- A clear linear pattern with points clustering around a line (Correct answer)
- All data points falling exactly on the x-axis
- Points alternating between high and low values
Correct answer: A clear linear pattern with points clustering around a line
A clear linear pattern in a scatter diagram suggests a potential relationship between the two variables, warranting further investigation.
CQIA Quality Tools & Techniques for Problem Solving 3
A histogram shows data that is skewed to the right.
This most likely indicates: