Complete Six Sigma Green Belt Test Bank with 200
Updated Exam-Style Questions, Detailed Explanations
for Every Answer, Plus Complete Coverage of DMAIC
Phases, Hypothesis Testing, FMEA, and Lean Six
Sigma Tools – Guaranteed Prep for Passing Your
Certification on the First Try
INTRODUCTION
Welcome to your Six Sigma Green Belt Certification Exam Success Guide. This guide
contains 200 numbered exam-style questions covering DMAIC, statistical tools,
process mapping, control charts, hypothesis testing, lean concepts, and more. Each
question includes a bold correct answer and a bold italic rationale explaining why the
answer is right. Whether you’re preparing for ASQ, IASSC, or any other Green Belt exam,
this guide will strengthen your understanding and boost your confidence.
QUESTIONS 1–50: FOUNDATIONS & DMAIC PHASES
1. What is the primary goal of Six Sigma?
A) Reduce defects to 3.4 per million opportunities
B) Eliminate all variation
C) Increase product cost
D) Shorten project timelines
,Answer: A) Reduce defects to 3.4 per million opportunities
Bold Italic Rationale: Six Sigma aims for 3.4 defects per million opportunities
(DPMO), which corresponds to a 99.99966% yield under the assumption of a 1.5σ
shift.
2. Which phase of DMAIC focuses on identifying root causes?
A) Define
B) Measure
C) Analyze
D) Improve
Answer: C) Analyze
Bold Italic Rationale: The Analyze phase uses statistical tools like hypothesis
testing and fishbone diagrams to identify and verify root causes of process
problems.
3. A process has a Cp of 0.8 and Cpk of 0.5. What does this indicate?
A) Process is centered but not capable
B) Process is not capable and not centered
C) Process is capable and centered
D) Process is capable but not centered
Answer: B) Process is not capable and not centered
*Bold Italic Rationale: Cp < 1 means lack of capability; Cpk < Cp indicates the
process is off-center. Both values <1 confirm inability to meet specifications.*
,4. Which tool is used to prioritize problems based on the 80/20 rule?
A) Fishbone diagram
B) Pareto chart
C) Control chart
D) Scatter plot
Answer: B) Pareto chart
*Bold Italic Rationale: The Pareto chart follows the 80/20 rule (80% of problems
come from 20% of causes) to highlight the most significant problems for
prioritization.*
5. What does a Run chart help detect?
A) Process mean shifts or trends
B) Root causes
C) Relationships between variables
D) Process capability
Answer: A) Process mean shifts or trends
Bold Italic Rationale: A Run chart plots data over time to identify trends, shifts,
runs, or patterns, such as a change in central tendency.
6. What is the purpose of a FMEA?
A) Identify potential failure modes and their effects
B) Calculate process sigma
C) Monitor process stability
D) Collect voice of customer
, Answer: A) Identify potential failure modes and their effects
Bold Italic Rationale: Failure Mode and Effects Analysis (FMEA) proactively
identifies how a process might fail and the impact of those failures, then prioritizes
actions by RPN.
7. In DMAIC, what is the main output of the Define phase?
A) Control charts
B) Project charter and high-level process map
C) Root causes
D) Implemented solutions
Answer: B) Project charter and high-level process map
Bold Italic Rationale: The Define phase produces the project charter (problem
statement, goal, scope, team) and a SIPOC or high-level map.
8. Which distribution is used for defect counts per unit?
A) Normal
B) Binomial
C) Poisson
D) Exponential
Answer: C) Poisson
Bold Italic Rationale: Poisson models discrete count data (defects per unit) when
the opportunity for defects is large but probability per opportunity is small.
Updated Exam-Style Questions, Detailed Explanations
for Every Answer, Plus Complete Coverage of DMAIC
Phases, Hypothesis Testing, FMEA, and Lean Six
Sigma Tools – Guaranteed Prep for Passing Your
Certification on the First Try
INTRODUCTION
Welcome to your Six Sigma Green Belt Certification Exam Success Guide. This guide
contains 200 numbered exam-style questions covering DMAIC, statistical tools,
process mapping, control charts, hypothesis testing, lean concepts, and more. Each
question includes a bold correct answer and a bold italic rationale explaining why the
answer is right. Whether you’re preparing for ASQ, IASSC, or any other Green Belt exam,
this guide will strengthen your understanding and boost your confidence.
QUESTIONS 1–50: FOUNDATIONS & DMAIC PHASES
1. What is the primary goal of Six Sigma?
A) Reduce defects to 3.4 per million opportunities
B) Eliminate all variation
C) Increase product cost
D) Shorten project timelines
,Answer: A) Reduce defects to 3.4 per million opportunities
Bold Italic Rationale: Six Sigma aims for 3.4 defects per million opportunities
(DPMO), which corresponds to a 99.99966% yield under the assumption of a 1.5σ
shift.
2. Which phase of DMAIC focuses on identifying root causes?
A) Define
B) Measure
C) Analyze
D) Improve
Answer: C) Analyze
Bold Italic Rationale: The Analyze phase uses statistical tools like hypothesis
testing and fishbone diagrams to identify and verify root causes of process
problems.
3. A process has a Cp of 0.8 and Cpk of 0.5. What does this indicate?
A) Process is centered but not capable
B) Process is not capable and not centered
C) Process is capable and centered
D) Process is capable but not centered
Answer: B) Process is not capable and not centered
*Bold Italic Rationale: Cp < 1 means lack of capability; Cpk < Cp indicates the
process is off-center. Both values <1 confirm inability to meet specifications.*
,4. Which tool is used to prioritize problems based on the 80/20 rule?
A) Fishbone diagram
B) Pareto chart
C) Control chart
D) Scatter plot
Answer: B) Pareto chart
*Bold Italic Rationale: The Pareto chart follows the 80/20 rule (80% of problems
come from 20% of causes) to highlight the most significant problems for
prioritization.*
5. What does a Run chart help detect?
A) Process mean shifts or trends
B) Root causes
C) Relationships between variables
D) Process capability
Answer: A) Process mean shifts or trends
Bold Italic Rationale: A Run chart plots data over time to identify trends, shifts,
runs, or patterns, such as a change in central tendency.
6. What is the purpose of a FMEA?
A) Identify potential failure modes and their effects
B) Calculate process sigma
C) Monitor process stability
D) Collect voice of customer
, Answer: A) Identify potential failure modes and their effects
Bold Italic Rationale: Failure Mode and Effects Analysis (FMEA) proactively
identifies how a process might fail and the impact of those failures, then prioritizes
actions by RPN.
7. In DMAIC, what is the main output of the Define phase?
A) Control charts
B) Project charter and high-level process map
C) Root causes
D) Implemented solutions
Answer: B) Project charter and high-level process map
Bold Italic Rationale: The Define phase produces the project charter (problem
statement, goal, scope, team) and a SIPOC or high-level map.
8. Which distribution is used for defect counts per unit?
A) Normal
B) Binomial
C) Poisson
D) Exponential
Answer: C) Poisson
Bold Italic Rationale: Poisson models discrete count data (defects per unit) when
the opportunity for defects is large but probability per opportunity is small.
