Lean Six Sigma Yellow Belt Certification FREE Lean Six Sigma Yellow Belt Root Cause Analysis Questions and Answers 2 — Questions and Answers
Question 1: Which root cause analysis tool uses repeated questioning to drill down from a symptom to its underlying cause?
- 5 Whys (Correct answer)
- Pareto Chart
- Control Chart
- SIPOC Diagram
Correct answer: 5 Whys
The 5 Whys technique involves asking 'why' repeatedly until the fundamental cause of a problem is identified.
Question 2: In a Cause-and-Effect diagram, what does the 'head' of the fish represent?
- The root cause
- The effect or problem (Correct answer)
- The category of causes
- The corrective action
Correct answer: The effect or problem
The head of the fishbone diagram represents the problem or effect being analyzed, while the bones represent potential causes.
Question 3: What is a key limitation of the 5 Whys technique?
- It requires statistical software
- It can follow only one causal path at a time (Correct answer)
- It cannot be used in manufacturing
- It must always reach exactly five levels
Correct answer: It can follow only one causal path at a time
The 5 Whys tends to follow a single chain of causation, potentially missing other contributing root causes.
Question 4: Which category is NOT one of the traditional 6Ms used in an Ishikawa diagram?
- Manpower
- Machine
- Money (Correct answer)
- Method
Correct answer: Money
The traditional 6Ms are Manpower, Machine, Material, Method, Measurement, and Mother Nature (Environment), not Money.
Question 5: What is the primary purpose of a fault tree analysis in root cause analysis?
- To assign blame to individuals
- To map logical relationships between failures and their causes (Correct answer)
- To calculate production costs
- To schedule preventive maintenance
Correct answer: To map logical relationships between failures and their causes
Fault tree analysis uses Boolean logic to map how combinations of lower-level failures can lead to a top-level undesired event.
Question 6: After identifying a root cause, what should be verified before implementing a corrective action?
- That the cause, when removed, actually prevents recurrence of the problem (Correct answer)
- That the cause was documented in a Pareto chart
- That at least five team members agree on the cause
- That the cause appears in the control plan
Correct answer: That the cause, when removed, actually prevents recurrence of the problem
A true root cause is confirmed by verifying that removing or addressing it prevents the problem from recurring.
