Lean Six Sigma Green Belt Comprehensive QUESTION Bank |
Complete Practice QUESTIONs & Verified Answers (2026/2027)
QUESTION 1
What is the primary purpose of creating a SIPOC diagram during the
Define phase of a DMAIC project?
• A. To calculate the exact financial return of the project.
• B. To provide a high-level visual overview of process boundaries,
suppliers, inputs, process steps, outputs, and customers.
• C. To conduct statistical hypothesis testing on raw data.
• D. To document detailed standard operating procedures for
operators.
Correct Answer: B. To provide a high-level visual overview of process
boundaries, suppliers, inputs, process steps, outputs, and customers.
Detailed Rationale: A SIPOC diagram keeps the team focused on the
macro level, defining where the process starts and ends, and identifying
key stakeholders before diving into detailed data collection.
QUESTION 2
How is Defects Per Million Opportunities (DPMO) calculated?
• A. (Total Defects/Total Units) × 1,000,000
• B. (Total Defects/(Total Units × Opportunities per Unit)) ×
1,000,000
• C. (Total Defective Units/Total Opportunities) × 1,000,000
, • D. (Total Opportunities/Total Defects) × 1,000,000
Correct Answer: B. (Total Defects/(Total Units ×
Opportunities per Unit)) × 1,000,000
Detailed Rationale: DPMO normalizes defect rates across different
processes by factoring in how many chances for error exist on a single
unit of product or service.
QUESTION 3
In the 8 Wastes of Lean (TIMWOODS), what does "Transportation"
waste refer to?
• A. Moving products or materials from one location to another
unnecessarily.
• B. Operators walking across the room to fetch tools.
• C. Shipping finished goods to the end customer.
• D. Employees commuting to work.
Correct Answer: A. Moving products or materials from one location to
another unnecessarily.
Detailed Rationale: Transportation waste involves any unnecessary
movement of materials between processes. Moving people is
categorized separately under "Motion."
QUESTION 4
Why is the Median often preferred over the Mean when analyzing
heavily skewed data?
• A. The median is easier to calculate manually.
, • B. The median is less sensitive to extreme outliers and extreme
values in skewed distributions.
• C. The median always equals the standard deviation.
• D. The mean cannot be used for continuous data.
Correct Answer: B. The median is less sensitive to extreme outliers and
extreme values in skewed distributions.
Detailed Rationale: Extreme outliers pull the mean toward the tail of a
skewed distribution, whereas the median represents the exact middle
point, providing a more robust measure of central tendency.
QUESTION 5
What is the primary objective of a Data Collection Plan in the Measure
phase?
• A. To ensure that data is gathered consistently, accurately, and
without operational bias to answer specific project QUESTIONs.
• B. To store old emails from management.
• C. To calculate employee payroll bonuses.
• D. To design new product packaging.
Correct Answer: A. To ensure that data is gathered consistently,
accurately, and without operational bias to answer specific project
QUESTIONs.
Detailed Rationale: A structured data collection plan defines what data
to collect, operational definitions, who will collect it, sample sizes, and
where it will be stored.
QUESTION 6
, Which root cause analysis tool uses iterative "Why" QUESTIONs to drill
down from a problem statement to its fundamental root cause?
• A. Fishbone Diagram
• B. 5 Whys
• C. Pareto Chart
• D. Process Map
Correct Answer: B. 5 Whys
Detailed Rationale: The 5 Whys technique encourages deep inquiry by
repeatedly asking "Why?" to peel away layers of symptoms until the
underlying root cause is revealed.
QUESTION 7
What is the primary purpose of conducting a pilot study during the
Improve phase?
• A. To permanently implement a solution globally without testing.
• B. To test a proposed solution on a small scale to evaluate its
effectiveness, uncover unforeseen issues, and refine the approach
before full-scale rollout.
• C. To train new hires on administrative tasks.
• D. To calculate historical defect rates.
Correct Answer: B. To test a proposed solution on a small scale to
evaluate its effectiveness, uncover unforeseen issues, and refine the
approach before full-scale rollout.
Complete Practice QUESTIONs & Verified Answers (2026/2027)
QUESTION 1
What is the primary purpose of creating a SIPOC diagram during the
Define phase of a DMAIC project?
• A. To calculate the exact financial return of the project.
• B. To provide a high-level visual overview of process boundaries,
suppliers, inputs, process steps, outputs, and customers.
• C. To conduct statistical hypothesis testing on raw data.
• D. To document detailed standard operating procedures for
operators.
Correct Answer: B. To provide a high-level visual overview of process
boundaries, suppliers, inputs, process steps, outputs, and customers.
Detailed Rationale: A SIPOC diagram keeps the team focused on the
macro level, defining where the process starts and ends, and identifying
key stakeholders before diving into detailed data collection.
QUESTION 2
How is Defects Per Million Opportunities (DPMO) calculated?
• A. (Total Defects/Total Units) × 1,000,000
• B. (Total Defects/(Total Units × Opportunities per Unit)) ×
1,000,000
• C. (Total Defective Units/Total Opportunities) × 1,000,000
, • D. (Total Opportunities/Total Defects) × 1,000,000
Correct Answer: B. (Total Defects/(Total Units ×
Opportunities per Unit)) × 1,000,000
Detailed Rationale: DPMO normalizes defect rates across different
processes by factoring in how many chances for error exist on a single
unit of product or service.
QUESTION 3
In the 8 Wastes of Lean (TIMWOODS), what does "Transportation"
waste refer to?
• A. Moving products or materials from one location to another
unnecessarily.
• B. Operators walking across the room to fetch tools.
• C. Shipping finished goods to the end customer.
• D. Employees commuting to work.
Correct Answer: A. Moving products or materials from one location to
another unnecessarily.
Detailed Rationale: Transportation waste involves any unnecessary
movement of materials between processes. Moving people is
categorized separately under "Motion."
QUESTION 4
Why is the Median often preferred over the Mean when analyzing
heavily skewed data?
• A. The median is easier to calculate manually.
, • B. The median is less sensitive to extreme outliers and extreme
values in skewed distributions.
• C. The median always equals the standard deviation.
• D. The mean cannot be used for continuous data.
Correct Answer: B. The median is less sensitive to extreme outliers and
extreme values in skewed distributions.
Detailed Rationale: Extreme outliers pull the mean toward the tail of a
skewed distribution, whereas the median represents the exact middle
point, providing a more robust measure of central tendency.
QUESTION 5
What is the primary objective of a Data Collection Plan in the Measure
phase?
• A. To ensure that data is gathered consistently, accurately, and
without operational bias to answer specific project QUESTIONs.
• B. To store old emails from management.
• C. To calculate employee payroll bonuses.
• D. To design new product packaging.
Correct Answer: A. To ensure that data is gathered consistently,
accurately, and without operational bias to answer specific project
QUESTIONs.
Detailed Rationale: A structured data collection plan defines what data
to collect, operational definitions, who will collect it, sample sizes, and
where it will be stored.
QUESTION 6
, Which root cause analysis tool uses iterative "Why" QUESTIONs to drill
down from a problem statement to its fundamental root cause?
• A. Fishbone Diagram
• B. 5 Whys
• C. Pareto Chart
• D. Process Map
Correct Answer: B. 5 Whys
Detailed Rationale: The 5 Whys technique encourages deep inquiry by
repeatedly asking "Why?" to peel away layers of symptoms until the
underlying root cause is revealed.
QUESTION 7
What is the primary purpose of conducting a pilot study during the
Improve phase?
• A. To permanently implement a solution globally without testing.
• B. To test a proposed solution on a small scale to evaluate its
effectiveness, uncover unforeseen issues, and refine the approach
before full-scale rollout.
• C. To train new hires on administrative tasks.
• D. To calculate historical defect rates.
Correct Answer: B. To test a proposed solution on a small scale to
evaluate its effectiveness, uncover unforeseen issues, and refine the
approach before full-scale rollout.
