Lean Six Sigma Yellow Belt Certification Root Cause Analysis 3

Question 1

Which of the following is a key limitation of the 5 Whys technique?

Accepted Answer

It can lead different teams to different root causes for the same problem

Answer

The 5 Whys is subjective, so different teams may follow different causal chains and arrive at different root causes.

Question 2

In root cause analysis, a 'symptom' is best defined as:

Accepted Answer

An observable sign that a problem exists, not the cause itself

Answer

A symptom is the visible evidence of a problem; effective RCA digs beneath symptoms to find the underlying cause.

Question 3

A Pareto chart shows that 80% of customer complaints come from 3 defect types. How does this support root cause analysis?

Accepted Answer

It prioritizes which defects to investigate first for maximum impact

Answer

A Pareto chart applies the 80/20 rule to prioritize the most significant defects so RCA efforts target the highest-impact problems.

Question 4

Which action would you take FIRST when starting a root cause analysis?

Accepted Answer

Clearly define and scope the problem statement

Answer

A clear, well-scoped problem statement is essential before any analysis begins, ensuring the team investigates the right issue.

Question 5

The '6 M's' used in fishbone diagrams for manufacturing processes include Machine, Method, Material, Man, and Measurement. What is the sixth 'M'?

Accepted Answer

Mother Nature (Environment)

Answer

The sixth M is Mother Nature or Environment, which covers external environmental conditions that can affect a process.

Lean Six Sigma Yellow Belt Certification Practice Test