CQIA Root Cause Analysis 4 — Questions and Answers
Question 1: Which of the following best describes the difference between corrective action and preventive action (CAPA)?
- Corrective action addresses future risks; preventive action fixes existing problems
- Corrective action fixes a current nonconformance; preventive action eliminates the risk of a potential nonconformance (Correct answer)
- Both terms refer to the same process under different names
- Preventive action is only used in healthcare settings
Correct answer: Corrective action fixes a current nonconformance; preventive action eliminates the risk of a potential nonconformance
Corrective action addresses an existing problem, while preventive action proactively eliminates potential problems before they occur.
Question 2: A run chart shows a shift of eight consecutive data points all below the centerline. This pattern suggests:
- Normal common cause variation
- A special cause that has shifted the process (Correct answer)
- The data is invalid and should be discarded
- The specification limits have changed
Correct answer: A special cause that has shifted the process
Eight or more consecutive points on one side of the centerline is a standard signal of a special (assignable) cause in the process.
Question 3: What is the role of a 'why-why diagram' in root cause analysis?
- It replaces a Pareto chart to rank defects
- It visually maps the chain of causes and effects from the symptom to the root cause (Correct answer)
- It plots cause frequency against cumulative percentage
- It shows the relationship between two variables
Correct answer: It visually maps the chain of causes and effects from the symptom to the root cause
A why-why (or why tree) diagram maps successive cause-and-effect relationships visually, showing the path from symptom to root cause.
Question 4: In RCA, which approach helps confirm that a proposed root cause is genuine by temporarily removing and reintroducing the suspected cause?
- Benchmarking
- Is/Is Not analysis
- Cause verification through controlled testing (Correct answer)
- Affinity grouping
Correct answer: Cause verification through controlled testing
Controlled testing — removing and reintroducing the suspected cause — confirms causality by showing that the effect disappears and returns accordingly.
Question 5: An 'Is/Is Not' matrix is MOST useful for:
- Calculating process capability
- Narrowing down the possible causes by comparing where and when the problem occurs versus where it does not (Correct answer)
- Setting control chart limits
- Ranking corrective actions by cost
Correct answer: Narrowing down the possible causes by comparing where and when the problem occurs versus where it does not
The Is/Is Not matrix contrasts conditions where the problem exists with conditions where it does not, helping eliminate unlikely causes.
Question 6: Which of the following is the LEAST effective root cause analysis outcome?
- Identifying a process redesign that prevents recurrence
- Retraining the operator who made the error without changing the process (Correct answer)
- Updating procedures and adding error-proofing
- Modifying the system to make the error impossible
Correct answer: Retraining the operator who made the error without changing the process
Retraining an individual without changing the underlying process is the least effective fix because the error-prone conditions remain unchanged.
Question 7: During an RCA facilitation, one team member dominates the discussion and others stay silent. The BEST facilitation technique to address this is:
- Ask the dominant member to leave the meeting
- Use structured brainstorming (e.g., round-robin) to ensure all voices are heard (Correct answer)
- Document only the dominant member's causes since they have the most experience
- Cancel the session and re-do it with a smaller group
Correct answer: Use structured brainstorming (e.g., round-robin) to ensure all voices are heard
Round-robin or nominal group technique ensures equal participation, preventing one voice from skewing the team's analysis.
CQIA Root Cause Analysis 4
Which of the following best describes the difference between corrective action and preventive action (CAPA)?