Six Sigma | DMAIC Lean Six Sigma Green Belt | 100+ MCQ with Answers
Q1. What is the primary goal of Six Sigma as a management philosophy?
A. Increasing output volume
B. Reducing process variation
C. Expanding product range
D. Enhancing marketing visibility
✅ Answer: B. Reducing process variation
Q2. In Six Sigma, what does the symbol σ (sigma) represent?
A. Process mean
B. Process capability
C. Standard deviation
D. Control limit
✅ Answer: C. Standard deviation
Q3. What is the first step once a process has become stable and in control?
A. Start a Six Sigma project
B. Collect more control charts
C. Train operators
D. Increase cycle time
✅ Answer: A. Start a Six Sigma project
Q4. Which of the following best describes a Non-Value Added (NVA) activity?
A. Adds to customer satisfaction directly
B. Cannot be eliminated due to compliance
C. Creates waste and should be minimized
D. Is a cost of doing business
✅ Answer: C. Creates waste and should be minimized
Q5. In Six Sigma, the variable ‘Y’ represents:
A. Process output
B. Process input
C. Control limit
D. Standard deviation
✅ Answer: A. Process output
Q6. What is the main objective of the Analyze phase?
A. Implementing solutions
B. Validating measurement systems
C. Identifying and validating critical X factors
D. Developing control plans
✅ Answer: C. Identifying and validating critical X factors
Q7. Which tool helps visualize multiple potential causes categorized by factors like Manpower, Machine, Material, etc.?
A. Pareto Chart
B. Fishbone Diagram
C. Control Chart
D. Scatter Plot
✅ Answer: B. Fishbone Diagram
Q8. The “Five Why” technique is primarily used for:
A. Brainstorming new ideas
B. Identifying the fundamental root cause
C. Prioritizing solutions
D. Statistical testing
✅ Answer: B. Identifying the fundamental root cause
Q9. In the Malgudi Hospital case, which factor showed a significant impact on registration time?
A. Printer Type
B. Training and Experience
C. Desk Layout
D. Stationary Supplier
✅ Answer: B. Training and Experience
Q10. The principle behind hypothesis testing in Six Sigma is to:
A. Accept the alternative hypothesis directly
B. Test whether an input (X) significantly affects the output (Y)
C. Confirm all variables affect the process equally
D. Replace subjective reasoning
✅ Answer: B. Test whether an input (X) significantly affects the output (Y)
Q11. What does a low p-value (e.g., < 0.05) in hypothesis testing indicate?
A. The null hypothesis should be accepted
B. The difference is statistically significant
C. The variable has no impact
D. The data lacks normality
✅ Answer: B. The difference is statistically significant
Q12. Which statistical test is best suited to compare means across multiple groups?
A. Chi-Square Test
B. Regression Analysis
C. ANOVA
D. F-Test
✅ Answer: C. ANOVA
Q13. What type of ANOVA was used in the Malgudi Hospital case to test Experience and Training jointly?
A. One Factor ANOVA
B. Two Factor ANOVA with Replication
C. T-Test
D. Correlation Analysis
✅ Answer: B. Two Factor ANOVA with Replication
Q14. In correlation analysis, a value of +1 indicates:
A. No relationship
B. Perfect positive correlation
C. Perfect negative correlation
D. High variability
✅ Answer: B. Perfect positive correlation
Q15. Regression analysis is used to:
A. Identify cause categories
B. Measure control limits
C. Show impact of independent variables on a dependent variable
D. Establish random errors
✅ Answer: C. Show impact of independent variables on a dependent variable
Q16. The Pareto principle is commonly known as:
A. 60–40 rule
B. 20–80 rule
C. 30–70 rule
D. 50–50 rule
✅ Answer: B. 20–80 rule
Q17. What does the box plot visually represent?
A. Process average
B. Data variability and distribution
C. Control limit violations
D. Only outliers
✅ Answer: B. Data variability and distribution
Q18. In the Malgudi Hospital case, which factor had no significant impact on registration time?
A. Printer Type
B. Language Barrier
C. Number of Printers
D. Training
✅ Answer: A. Printer Type
Q19. “Go and See” or Gemba Walk is used to:
A. Audit compliance forms
B. Observe the process in real conditions
C. Compare employee productivity
D. Review documentation
✅ Answer: B. Observe the process in real conditions
Q20. A process that contains both VA (87 sec) and NVA (94 sec) time must prioritize:
A. Increasing VA time
B. Removing NVA time
C. Rebalancing shifts
D. Hiring more staff
✅ Answer: B. Removing NVA time
Q21. Which phase follows Analyze in the DMAIC cycle?
A. Define
B. Improve
C. Measure
D. Control
✅ Answer: B. Improve
Q22. Benchmarking in the Improve phase helps to:
A. Reduce data collection
B. Find proven external solutions
C. Avoid pilot testing
D. Eliminate statistical tests
✅ Answer: B. Find proven external solutions
Q23. The SCAMPER tool is used for:
A. Process validation
B. Idea generation and creative improvement
C. Process control
D. Sigma level calculation
✅ Answer: B. Idea generation and creative improvement
Q24. The acronym SCAMPER stands for Substitute, Combine, Add, Modify, Put to use, Eliminate, and:
A. Reinforce
B. Reassign
C. Reverse
D. Restructure
✅ Answer: C. Reverse
Q25. What is the main function of the Pugh Matrix?
A. Data validation
B. Solution selection and comparison
C. Project scheduling
D. Statistical testing
✅ Answer: B. Solution selection and comparison
Q26. Which of the following is an example of Functional Benchmarking?
A. Comparing two competing hospitals
B. Comparing a hospital’s registration process with airport check-in efficiency
C. Comparing within different hospital branches
D. Comparing billing to pharmacy
✅ Answer: B. Comparing a hospital’s registration process with airport check-in efficiency
Q27. The purpose of pilot implementation is to:
A. Replace full-scale implementation
B. Test solutions on a smaller scale
C. Delay execution
D. Collect training data only
✅ Answer: B. Test solutions on a smaller scale
Q28. In hypothesis testing after improvement, the alternate hypothesis is that:
A. Process time remains same
B. Process time has reduced
C. Process variation increases
D. Process mean is unchanged
✅ Answer: B. Process time has reduced
Q29. FMEA (Failure Mode and Effects Analysis) helps in:
A. Estimating project duration
B. Preventing recurrence of process errors
C. Reducing headcount
D. Enhancing sampling frequency
✅ Answer: B. Preventing recurrence of process errors
Q30. Which of the following is NOT a type of benchmarking?
A. Competitive
B. Functional
C. Financial
D. General
✅ Answer: C. Financial
Q31. The Taguchi Method is primarily used for:
A. Estimating sample size
B. Process redesign with multiple factors
C. Identifying measurement errors
D. Time-series forecasting
✅ Answer: B. Process redesign with multiple factors
Q32. What does an orthogonal array in Design of Experiment (DoE) ensure?
A. Minimal number of experiments with valid results
B. Full factorial coverage
C. Randomized trial selection
D. Sequential sampling
✅ Answer: A. Minimal number of experiments with valid results
Q33. In Six Sigma terms, ‘Critical Xs’ refer to:
A. Inputs with significant impact on output
B. Output defects
C. Process averages
D. Team leaders
✅ Answer: A. Inputs with significant impact on output
Q34. The Malgudi case used which statistical test to confirm impact of number of printers?
A. Regression Analysis
B. Hypothesis Testing
C. Chi-square Test
D. Control Chart
✅ Answer: B. Hypothesis Testing
Q35. The goal of the Improve phase is to:
A. Identify potential Xs
B. Validate root causes
C. Implement solutions and verify impact
D. Measure baseline data
✅ Answer: C. Implement solutions and verify impact
Q36. Which of these best defines a Value Stream Map (VSM)?
A. A visual tool showing the flow of materials and information
B. A financial performance report
C. A project timeline chart
D. A process control plan
✅ Answer: A. A visual tool showing the flow of materials and information
Q37. What is the outcome of value stream analysis in the Malgudi case?
A. More NVA than VA time
B. More VA than NVA time
C. Equal VA and NVA time
D. Only VA time recorded
✅ Answer: A. More NVA than VA time
Q38. When a variable’s P-value is high (>0.05), it means:
A. The variable has a significant impact
B. The null hypothesis is rejected
C. There is no significant impact
D. The process is unstable
✅ Answer: C. There is no significant impact
Q39. Which of the following tools supports prioritization of causes?
A. Pugh Matrix
B. Pareto Analysis
C. Control Chart
D. Regression Line
✅ Answer: B. Pareto Analysis
Q40. What is the next step after identifying significant X factors in Analyze phase?
A. Start Control charts
B. Move to Improve phase
C. Conduct Measure phase again
D. Define new metrics
✅ Answer: B. Move to Improve phase
Q41. Which of the following was a major ergonomic issue in the Malgudi case?
A. Overstaffing
B. Poor counter design
C. Overprinting
D. Lack of doctor availability
✅ Answer: B. Poor counter design
Q42. What does the Control Limit indicate in process behavior charts?
A. Acceptable process variation
B. Specification tolerance
C. Measurement range
D. Mean value
✅ Answer: A. Acceptable process variation
Q43. What statistical tool helps visualize group median and interquartile range?
A. Histogram
B. Box Plot
C. Scatter Plot
D. Line Graph
✅ Answer: B. Box Plot
Q44. Which of these tools can confirm the collective effect of two independent factors?
A. Two-Factor ANOVA
B. Simple Regression
C. Chi-square Test
D. Gage R&R
✅ Answer: A. Two-Factor ANOVA
Q45. A correlation coefficient near zero indicates:
A. Strong relationship
B. No significant linear relationship
C. Perfect dependency
D. Data is non-numeric
✅ Answer: B. No significant linear relationship
Q46. The difference between Hypothesis Testing and ANOVA is that:
A. ANOVA compares more than two groups
B. Hypothesis testing cannot reject H₀
C. ANOVA has no P-value
D. Hypothesis testing is non-statistical
✅ Answer: A. ANOVA compares more than two groups
Q47. A high Sigma Level implies:
A. Higher variation
B. Lower defect rate
C. Higher error probability
D. Process instability
✅ Answer: B. Lower defect rate
Q48. What kind of factor is “Experience” in the Malgudi case?
A. Qualitative Critical X
B. Quantitative Y variable
C. Noise factor
D. Control limit variable
✅ Answer: A. Qualitative Critical X
Q49. Which of the following ensures sustainability of improvements?
A. Root Cause Analysis
B. Control Phase Activities
C. Pilot Testing
D. Measurement Systems Analysis
✅ Answer: B. Control Phase Activities
Q50. The Define–Measure–Analyze–Improve–Control (DMAIC) cycle is intended for:
A. New process design
B. Existing process improvement
C. Product prototyping
D. Market testing
✅ Answer: B. Existing process improvement
Q51. The Control phase in Six Sigma aims to:
A. Identify potential causes
B. Sustain gains achieved in the Improve phase
C. Design new processes
D. Increase sampling size
✅ Answer: B. Sustain gains achieved in the Improve phase
Q52. Which document defines the standard method of process execution post-improvement?
A. Process Charter
B. Standard Operating Procedure (SOP)
C. Data Sheet
D. Fishbone Diagram
✅ Answer: B. Standard Operating Procedure (SOP)
Q53. What tool is commonly used in Control phase to monitor ongoing performance?
A. Control Chart
B. Histogram
C. Cause and Effect Matrix
D. Benchmark Matrix
✅ Answer: A. Control Chart
Q54. Which of these metrics quantifies process capability relative to specification limits?
A. Cp
B. P-Value
C. Mean
D. Sigma
✅ Answer: A. Cp
Q55. What does a Cp value of 1.33 generally indicate?
A. Process is incapable
B. Process is marginally capable
C. Process is capable and acceptable
D. Process needs redesign
✅ Answer: C. Process is capable and acceptable
Q56. Cpk differs from Cp by accounting for:
A. Process cost
B. Process centering
C. Output volume
D. Data distribution type
✅ Answer: B. Process centering
Q57. What does DPMO stand for in Six Sigma metrics?
A. Defects Per Million Opportunities
B. Deviations Per Manufacturing Output
C. Defects Per Mean Output
D. Data Points Measured Objectively
✅ Answer: A. Defects Per Million Opportunities
Q58. A Six Sigma level process produces approximately how many defects per million opportunities?
A. 233
B. 3.4
C. 10
D. 100
✅ Answer: B. 3.4
Q59. What does a higher Sigma level signify?
A. Higher variation
B. Lower defects
C. Lower productivity
D. Higher rework rate
✅ Answer: B. Lower defects
Q60. In the Malgudi case, after implementing improvements, the new sigma level would likely:
A. Decrease
B. Remain constant
C. Increase
D. Become unstable
✅ Answer: C. Increase
Q61. Which Six Sigma role is responsible for overall deployment strategy and alignment with business goals?
A. Black Belt
B. Green Belt
C. Champion
D. Process Owner
✅ Answer: C. Champion
Q62. The Black Belt’s primary responsibility is:
A. Statistical leadership of projects
B. Budget allocation
C. Executive sponsorship
D. Process maintenance
✅ Answer: A. Statistical leadership of projects
Q63. Which role ensures daily process control and sustains the improved process?
A. Green Belt
B. Master Black Belt
C. Process Owner
D. Champion
✅ Answer: C. Process Owner
Q64. The term “Critical to Quality (CTQ)” refers to:
A. Key quality parameters defined by the customer
B. Financial cost drivers
C. Process inputs
D. Statistical averages
✅ Answer: A. Key quality parameters defined by the customer
Q65. Which document tracks project progress, key metrics, and milestones?
A. Project Charter
B. Process Map
C. Control Plan
D. Work Breakdown Sheet
✅ Answer: A. Project Charter
Q66. A Control Plan primarily helps in:
A. Measuring Y variables
B. Standardizing process control and accountability
C. Designing experiments
D. Recording brainstorming outcomes
✅ Answer: B. Standardizing process control and accountability
Q67. Which chart is used to detect assignable causes of variation?
A. Pareto Chart
B. Control Chart
C. Scatter Diagram
D. Box Plot
✅ Answer: B. Control Chart
Q68. In Control Charts, points beyond control limits indicate:
A. Random variation
B. Common cause variation
C. Special cause variation
D. Process stability
✅ Answer: C. Special cause variation
Q69. What is the typical number of standard deviations between control limits in an X-bar chart?
A. 1
B. 2
C. 3
D. 6
✅ Answer: C. 3
Q70. A process operating at 4 Sigma level has approximately how many defects per million?
A. 3.4
B. 6,210
C. 233
D. 10,000
✅ Answer: B. 6,210
Q71. The Voice of Customer (VOC) is critical during which DMAIC phase?
A. Define
B. Measure
C. Control
D. Improve
✅ Answer: A. Define
Q72. Which measure best represents long-term process capability?
A. Cp
B. Cpk
C. Ppk
D. R-bar
✅ Answer: C. Ppk
Q73. The main difference between Cp and Ppk is:
A. Cp uses short-term data, Ppk uses long-term data
B. Ppk ignores centering
C. Cp adjusts for variation
D. Ppk cannot be used in Control phase
✅ Answer: A. Cp uses short-term data, Ppk uses long-term data
Q74. Measurement System Analysis (MSA) ensures that:
A. Instruments are calibrated
B. Data collection is reliable and accurate
C. Operators are certified
D. Process limits are stable
✅ Answer: B. Data collection is reliable and accurate
Q75. Gage R&R is a key component of which DMAIC phase?
A. Define
B. Measure
C. Analyze
D. Control
✅ Answer: B. Measure
Q76. The concept of COPQ (Cost of Poor Quality) includes:
A. Only external failure cost
B. All costs related to inefficiencies and rework
C. Fixed operating cost
D. Marketing cost
✅ Answer: B. All costs related to inefficiencies and rework
Q77. Which is NOT one of the typical categories in a Fishbone Diagram?
A. Measurement
B. Method
C. Money
D. Machine
✅ Answer: C. Money
Q78. “Eliminate” in the SCAMPER technique suggests:
A. Combining two processes
B. Removing non-value activities
C. Adding new steps
D. Standardizing procedures
✅ Answer: B. Removing non-value activities
Q79. A stable process is characterized by:
A. Constant mean and variation within limits
B. Large shifts over time
C. Random control chart pattern
D. Unpredictable sigma values
✅ Answer: A. Constant mean and variation within limits
Q80. What type of data is most suitable for ANOVA analysis?
A. Nominal
B. Ordinal
C. Interval/Ratio
D. Categorical only
✅ Answer: C. Interval/Ratio
Q81. Control charts are ineffective when:
A. Data are not collected chronologically
B. Sample size is large
C. Variability is low
D. Sigma level is 6
✅ Answer: A. Data are not collected chronologically
Q82. The concept of “Centering” in process control means:
A. Process mean equals the target value
B. Control limits are equal
C. Process is over-specified
D. Operator bias is reduced
✅ Answer: A. Process mean equals the target value
Q83. Process capability is defined as the ratio between:
A. Control limits and tolerance
B. Specification width and process width
C. Mean and standard deviation
D. DPMO and Cp
✅ Answer: B. Specification width and process width
Q84. The Y = f(X) model implies that:
A. Output is a function of input variables
B. Input depends on output variation
C. Both Y and X are constants
D. Sigma affects inputs directly
✅ Answer: A. Output is a function of input variables
Q85. A P-value greater than 0.05 implies:
A. Reject the null hypothesis
B. Accept the null hypothesis
C. Data not significant
D. Model invalid
✅ Answer: B. Accept the null hypothesis
Q86. The F-test in ANOVA measures:
A. Variance ratio among groups
B. Frequency distribution
C. Factor loadings
D. Linear correlation
✅ Answer: A. Variance ratio among groups
Q87. A regression R² value close to 1 indicates:
A. Poor model fit
B. Strong relationship between variables
C. Random correlation
D. Overfitting
✅ Answer: B. Strong relationship between variables
Q88. Which of the following is considered a “Special Cause” of variation?
A. Regular staff shift
B. Power failure during process
C. Natural measurement error
D. Inherent system variation
✅ Answer: B. Power failure during process
Q89. Control phase verification often involves:
A. Running another pilot test
B. Performing post-implementation T-tests
C. Conducting new root cause analysis
D. Brainstorming again
✅ Answer: B. Performing post-implementation T-tests
Q90. A process running at 2 Sigma produces approximately how many defects per million?
A. 308,537
B. 66,807
C. 6,210
D. 3.4
✅ Answer: B. 66,807
Q91. Lean methodology complements Six Sigma primarily by:
A. Reducing waste and cycle time
B. Increasing variance
C. Adding new measurements
D. Eliminating statistical testing
✅ Answer: A. Reducing waste and cycle time
Q92. When should a Control Plan be revised?
A. After every shift
B. When process changes occur
C. Every financial year
D. At the end of training
✅ Answer: B. When process changes occur
Q93. The Sigma level of a process is determined using:
A. Mean shift and DPMO
B. R-bar and Cp
C. Process map and VOC
D. Scatter diagram
✅ Answer: A. Mean shift and DPMO
Q94. A process with Cpk < 1 indicates:
A. Process is capable
B. Process is not meeting specifications
C. Process mean equals target
D. Sigma level > 6
✅ Answer: B. Process is not meeting specifications
Q95. In Six Sigma, “Hidden Factory” refers to:
A. Product warehouse
B. Efforts spent on rework and correction
C. Outsourced suppliers
D. Training center
✅ Answer: B. Efforts spent on rework and correction
Q96. The formula for Cp is:
A. (USL - LSL) / (6σ)
B. (USL + LSL) / σ
C. (6σ) / (USL - LSL)
D. (Mean / σ)
✅ Answer: A. (USL - LSL) / (6σ)
Q97. A control chart showing eight consecutive points on one side of mean indicates:
A. Random variation
B. A process shift
C. Measurement error
D. Lack of sampling
✅ Answer: B. A process shift
Q98. The main purpose of Mistake Proofing (Poka Yoke) is to:
A. Train operators faster
B. Prevent recurrence of human errors
C. Control data variation
D. Eliminate process documentation
✅ Answer: B. Prevent recurrence of human errors
Q99. What kind of data is suitable for control charts like p-chart?
A. Attribute data (defective items)
B. Continuous data (time, weight)
C. Nominal data
D. Ordinal ranking
✅ Answer: A. Attribute data (defective items)
Q100. Which Six Sigma tool helps visualize process flow, bottlenecks, and waiting times?
A. Value Stream Map (VSM)
B. Histogram
C. Fishbone Diagram
D. Box Plot
✅ Answer: A. Value Stream Map (VSM)
Q101. The Improve phase validates solutions through:
A. Full-scale implementation
B. Controlled pilot runs
C. Benchmark audit
D. Brainstorming
✅ Answer: B. Controlled pilot runs
Q102. When both Cp and Cpk are equal, it indicates:
A. Process is centered
B. Process is unstable
C. Measurement errors
D. Sigma shift
✅ Answer: A. Process is centered
Q103. VOC, VOB, and VOP respectively stand for:
A. Voice of Customer, Business, Process
B. Voice of Client, Benchmark, Production
C. Value of Customer, Objective, Plan
D. Variation of Control, Benchmark, Product
✅ Answer: A. Voice of Customer, Business, Process
Q104. The key deliverable at the end of Control phase is:
A. Baseline capability
B. Control Plan and SOP updates
C. Root Cause list
D. Brainstorm report
✅ Answer: B. Control Plan and SOP updates
Q105. The concept of "Sigma Shift" accounts for:
A. Short-term and long-term process variation difference
B. Machine calibration drift
C. Data rounding
D. Supplier delays
✅ Answer: A. Short-term and long-term process variation difference
Q106. A process with a Cpk of 2 corresponds roughly to:
A. 3 Sigma
B. 4 Sigma
C. 5 Sigma
D. 6 Sigma
✅ Answer: D. 6 Sigma
Q107. During the Analyze phase, Pareto analysis is most helpful in:
A. Prioritizing root causes
B. Identifying customers
C. Developing control charts
D. Designing experiments
✅ Answer: A. Prioritizing root causes
Q108. Which Six Sigma phase includes re-collection of data to confirm improved performance?
A. Define
B. Measure
C. Control
D. Analyze
✅ Answer: C. Control
Q109. The Control phase focuses on which type of variation?
A. Special cause
B. Common cause
C. Random
D. Measurement
✅ Answer: B. Common cause
Q110. The final indicator of Six Sigma project success is:
A. Improved Sigma Level with sustained performance
B. Number of meetings conducted
C. Cost of measurement system
D. Staff count reduction
✅ Answer: A. Improved Sigma Level with sustained performance
Six Sigma MCQs, DMAIC MCQ, Lean Six Sigma Green Belt questions, Six Sigma practice test, Cp Cpk Sigma level quiz, hypothesis testing in Six Sigma, ANOVA Six Sigma, Pareto analysis, Malgudi hospital case study, process capability metrics
