CAPA Investigation Techniques 2 — Questions and Answers
Question 1: Which technique involves asking 'why' repeatedly until the fundamental cause of a problem is identified?
- Fault Tree Analysis
- 5 Whys (Correct answer)
- Cause-and-Effect Diagram
- Pareto Analysis
Correct answer: 5 Whys
The 5 Whys technique iteratively asks 'why' (typically five times) to drill down from symptoms to root causes.
Question 2: In a CAPA investigation, what is the primary purpose of a Fault Tree Analysis (FTA)?
- To rank defects by frequency
- To map all possible causes leading to an undesired top event using logic gates (Correct answer)
- To identify the fastest corrective action
- To assign responsibility for failures
Correct answer: To map all possible causes leading to an undesired top event using logic gates
FTA uses Boolean logic gates to systematically map combinations of failures or events that can lead to a defined top-level undesired outcome.
Question 3: When conducting a failure investigation, 'preservation of evidence' is critical primarily because:
- It satisfies customer complaint documentation requirements
- Physical evidence may degrade or be lost, making root cause identification impossible later (Correct answer)
- Regulators require photographic evidence for all CAPAs
- It allows the investigation to be closed faster
Correct answer: Physical evidence may degrade or be lost, making root cause identification impossible later
Evidence preservation ensures that physical samples, conditions, and data are secured before they can degrade, be altered, or discarded, which is essential for accurate root cause analysis.
Question 4: A 'contributing cause' in a CAPA investigation is best described as:
- The single cause that directly created the nonconformance
- A factor that increased the likelihood or severity of the problem but did not cause it alone (Correct answer)
- A cause identified only after the corrective action is implemented
- The systemic cause identified during escape point analysis
Correct answer: A factor that increased the likelihood or severity of the problem but did not cause it alone
Contributing causes are factors that worsen or facilitate a problem but are not the direct root cause; addressing them strengthens corrective actions.
Question 5: Which investigation approach is MOST appropriate when a problem involves complex interactions among multiple subsystems?
- 5 Whys
- Fault Tree Analysis (Correct answer)
- Run Chart
- Stratification
Correct answer: Fault Tree Analysis
FTA excels at revealing how combinations of subsystem failures interact through logic gates to produce a top-level failure in complex systems.
Question 6: During an investigation interview, open-ended questions are preferred over closed-ended questions because they:
- Limit responses to yes or no, saving time
- Encourage the interviewee to provide detailed narrative information (Correct answer)
- Ensure consistent data collection across multiple investigations
- Reduce bias by restricting answer options
Correct answer: Encourage the interviewee to provide detailed narrative information
Open-ended questions invite elaboration and narrative responses, uncovering details and context that closed yes/no questions would miss.
Question 7: The 'escape point' in a root cause analysis refers to:
- The location where the defective product was shipped
- The earliest point in the process where the problem could have been detected but was not (Correct answer)
- The step where the defect was first introduced
- The control that prevented a more serious outcome
Correct answer: The earliest point in the process where the problem could have been detected but was not
The escape point identifies the detection opportunity that was missed, guiding improvements to inspection and monitoring controls.
CAPA Investigation Techniques 2
Which technique involves asking 'why' repeatedly until the fundamental cause of a problem is identified?