Six Sigma | DMAIC, Process Capability, and Measure Phase Concepts | 100+ MCQ with Answers
Q1. Six Sigma is primarily a:
A. Financial analysis system
B. Data-driven improvement methodology
C. Product marketing framework
D. Customer segmentation tool
✅ Answer: B. Data-driven improvement methodology
Q2. The central objective of Six Sigma is to:
A. Increase sales revenue
B. Decrease process variation and defects
C. Maximize product range
D. Simplify business structures
✅ Answer: B. Decrease process variation and defects
Q3. Which of the following best defines “Quality”?
A. Aesthetics of a product
B. Fitness for purpose
C. Profitability
D. Product popularity
✅ Answer: B. Fitness for purpose
Q4. Why are tolerances or specification limits critical in Six Sigma?
A. They define acceptable levels of variation
B. They are optional for process control
C. They simplify financial reporting
D. They eliminate the need for measurement
✅ Answer: A. They define acceptable levels of variation
Q5. CTQs (Critical to Quality) are derived from:
A. Voice of Competitors (VOCOMP)
B. Voice of Customer (VOC) or Voice of Business (VOB)
C. Marketing analytics
D. Supplier feedback
✅ Answer: B. Voice of Customer (VOC) or Voice of Business (VOB)
Q6. Which phase of DMAIC defines the project scope and objectives?
A. Measure
B. Analyze
C. Define
D. Control
✅ Answer: C. Define
Q7. The Project Charter in Six Sigma typically does not include:
A. Problem Statement
B. Goal Statement
C. Competitor Benchmarking
D. Scope Statement
✅ Answer: C. Competitor Benchmarking
Q8. A SIPOC diagram is used in which DMAIC phase?
A. Measure
B. Define
C. Analyze
D. Control
✅ Answer: B. Define
Q9. In Six Sigma, "Y" represents:
A. Process inputs
B. Process output (dependent variable)
C. Customer complaint rate
D. Sigma level
✅ Answer: B. Process output (dependent variable)
Q10. The Analyze phase primarily focuses on:
A. Controlling improvements
B. Measuring defects
C. Identifying critical X factors
D. Calculating ROI
✅ Answer: C. Identifying critical X factors
Q11. Which role in Six Sigma provides resources and defines the project?
A. Master Black Belt
B. Green Belt
C. Champion/Sponsor
D. Yellow Belt
✅ Answer: C. Champion/Sponsor
Q12. Green Belts are typically:
A. Full-time project leaders
B. Executive sponsors
C. Part-time project contributors
D. Data collection specialists only
✅ Answer: C. Part-time project contributors
Q13. The primary goal of the Measure phase is to:
A. Identify project goals
B. Measure current performance
C. Control future outcomes
D. Create process maps
✅ Answer: B. Measure current performance
Q14. Measurement System Analysis (MSA) helps to:
A. Improve operator skills
B. Identify contribution of measurement variation
C. Create VOC data
D. Reduce cost per defect
✅ Answer: B. Identify contribution of measurement variation
Q15. Total observed variation is a combination of:
A. Product variation and customer variation
B. Process variation and measurement variation
C. Operator variation and supplier variation
D. Internal and external failure costs
✅ Answer: B. Process variation and measurement variation
Q16. Gauge R&R stands for:
A. Repeatability and Reliability
B. Repeatability and Reproducibility
C. Reliability and Robustness
D. Regression and Randomness
✅ Answer: B. Repeatability and Reproducibility
Q17. In MSA, “Accuracy” refers to:
A. How close measurements are to each other
B. How close measurements are to the true value
C. The variation among multiple operators
D. The number of measurements taken
✅ Answer: B. How close measurements are to the true value
Q18. Which of the following is not part of accuracy metrics?
A. Bias
B. Linearity
C. Stability
D. Repeatability
✅ Answer: D. Repeatability
Q19. “Bias” in measurement indicates:
A. Variation between operators
B. Difference between measured and true value
C. Change in calibration frequency
D. Repeatability error
✅ Answer: B. Difference between measured and true value
Q20. “Linearity” refers to:
A. Stability of results over time
B. Change in bias over the range of operation
C. Random operator errors
D. Process reproducibility
✅ Answer: B. Change in bias over the range of operation
Q21. “Repeatability” variation is due to:
A. Instrument or equipment
B. Operator
C. Customer specification
D. Time delay
✅ Answer: A. Instrument or equipment
Q22. “Reproducibility” variation is caused by:
A. Different operators
B. Different instruments
C. Environmental temperature
D. Supplier differences
✅ Answer: A. Different operators
Q23. Gauge R&R percentage less than 10% indicates:
A. Poor system
B. Acceptable measurement system
C. Marginal system
D. Unstable process
✅ Answer: B. Acceptable measurement system
Q24. For attribute data, acceptable accuracy should be:
A. 70%
B. 80%
C. 90% or more
D. 50%
✅ Answer: C. 90% or more
Q25. Miss error in attribute data must be less than:
A. 2%
B. 5%
C. 10%
D. 15%
✅ Answer: A. 2%
Q26. False Alarm error in attribute data should be below:
A. 1%
B. 2%
C. 5%
D. 10%
✅ Answer: C. 5%
Q27. In Gauge R&R study, typically we need at least:
A. 5 parts
B. 10 parts, 2–3 operators, and 2–3 trials
C. 20 parts, 1 operator
D. 15 operators
✅ Answer: B. 10 parts, 2–3 operators, and 2–3 trials
Q28. “Defect” is defined as:
A. Entire product rejection
B. Departure from specification
C. Reworked part
D. Scrap material
✅ Answer: B. Departure from specification
Q29. “Defective” means:
A. Minor deviation
B. Product acceptable after repair
C. Product unacceptable due to one or more defects
D. Supplier variation
✅ Answer: C. Product unacceptable due to one or more defects
Q30. DPU represents:
A. Defects per Unit
B. Defectives per Unit
C. Dollars per Unit
D. Deliveries per Unit
✅ Answer: A. Defects per Unit
Q31. DPMO provides a basis for:
A. Financial benchmarking
B. Comparing processes with different complexities
C. Marketing campaigns
D. Reducing operator training time
✅ Answer: B. Comparing processes with different complexities
Q32. The ideal Six Sigma process produces:
A. 6.4 defects per million
B. 3.4 defects per million opportunities
C. 34 defects per thousand
D. Zero defects
✅ Answer: B. 3.4 defects per million opportunities
Q33. First Pass Yield (FPY) excludes:
A. Scrap
B. Rework
C. New design defects
D. Process downtime
✅ Answer: B. Rework
Q34. Rolled Throughput Yield (RTY) is computed by:
A. Adding yields of each step
B. Multiplying yields of each process step
C. Averaging process efficiencies
D. Subtracting defect rates
✅ Answer: B. Multiplying yields of each process step
Q35. USL and LSL represent:
A. Process control limits
B. Customer specification limits
C. Historical averages
D. Equipment settings
✅ Answer: B. Customer specification limits
Q36. Control limits are calculated from:
A. Customer tolerance
B. Natural process variation
C. Business goals
D. Benchmark data
✅ Answer: B. Natural process variation
Q37. In Process Control, we aim to:
A. Eliminate natural variation
B. Eliminate assignable causes
C. Change specifications
D. Increase measurement bias
✅ Answer: B. Eliminate assignable causes
Q38. In Six Sigma, we aim to:
A. Attack natural variation
B. Maintain process variation
C. Increase tolerances
D. Improve marketing ROI
✅ Answer: A. Attack natural variation
Q39. Cp and Cpk are applicable for:
A. Attribute data
B. Variable (continuous) data
C. Nominal data
D. Text data
✅ Answer: B. Variable (continuous) data
Q40. The Germ Magic case demonstrates:
A. Supplier management
B. Process capability using fill volume data
C. Cost reduction analysis
D. VOC gathering
✅ Answer: B. Process capability using fill volume data
Q41. Underfilling in Germ Magic was categorized as:
A. Overproduction waste
B. Lower specification defect
C. Measurement bias
D. Sampling error
✅ Answer: B. Lower specification defect
Q42. Overfilling causes which type of loss?
A. Customer loss
B. Material waste
C. Variation in operator bias
D. Sampling inconsistency
✅ Answer: B. Material waste
Q43. MSA “Stability” is used to evaluate:
A. Calibration frequency over time
B. Bias variation across operators
C. Process yield
D. Gauge R&R
✅ Answer: A. Calibration frequency over time
Q44. The Tollgate Review occurs:
A. Only at project completion
B. After each DMAIC phase
C. Before project approval
D. During training sessions
✅ Answer: B. After each DMAIC phase
Q45. Which metric measures the number of defective items per million?
A. DPU
B. DPMO
C. PPM
D. FPY
✅ Answer: C. PPM
Q46. When Gauge R&R > 30%, the system is:
A. Acceptable
B. Needs improvement
C. Unacceptable
D. Stable
✅ Answer: C. Unacceptable
Q47. The DMAIC framework stands for:
A. Define, Measure, Analyze, Improve, Control
B. Design, Monitor, Assess, Integrate, Conclude
C. Define, Manage, Audit, Inspect, Correct
D. Develop, Measure, Align, Innovate, Control
✅ Answer: A. Define, Measure, Analyze, Improve, Control
Q48. The “Voice of Business” (VOB) reflects:
A. Customer satisfaction
B. Internal business priorities and profitability
C. Supplier quality
D. Employee engagement
✅ Answer: B. Internal business priorities and profitability
Q49. Which phase identifies and validates “critical Xs”?
A. Define
B. Measure
C. Analyze
D. Control
✅ Answer: C. Analyze
Q50. Which Six Sigma belt collects data and assists part-time?
A. Green Belt
B. Yellow Belt
C. White Belt
D. Master Black Belt
✅ Answer: B. Yellow Belt
Q51. The main objective of the Analyze phase is to:
A. Confirm measurement accuracy
B. Identify root causes of variation
C. Collect process data
D. Implement control charts
✅ Answer: B. Identify root causes of variation
Q52. A common tool used to identify root causes in the Analyze phase is:
A. Pareto Chart
B. Check Sheet
C. Control Plan
D. Gantt Chart
✅ Answer: A. Pareto Chart
Q53. The 80/20 principle applied through a Pareto chart suggests:
A. 80% of defects come from 20% of causes
B. 20% of defects come from 80% of causes
C. 80% of time is spent measuring 20% of processes
D. 20% of yield defines 80% of performance
✅ Answer: A. 80% of defects come from 20% of causes
Q54. A Cause-and-Effect Diagram is also known as:
A. Pareto Chart
B. Fishbone or Ishikawa Diagram
C. Scatter Plot
D. Box Plot
✅ Answer: B. Fishbone or Ishikawa Diagram
Q55. The purpose of a Fishbone Diagram is to:
A. Display process flow
B. Identify possible causes for a problem
C. Prioritize projects
D. Measure process yield
✅ Answer: B. Identify possible causes for a problem
Q56. The term Y = f(X) represents:
A. Yield as a function of cost
B. Output as a function of input factors
C. Variance as a function of waste
D. Process improvement formula
✅ Answer: B. Output as a function of input factors
Q57. Scatter plots are used to:
A. Visualize relationships between variables
B. Estimate process cost
C. Display categorical data
D. Assess operator performance
✅ Answer: A. Visualize relationships between variables
Q58. Regression analysis in Six Sigma helps to:
A. Establish causal relationships between X and Y
B. Compare means of two samples
C. Create control charts
D. Develop SIPOC diagrams
✅ Answer: A. Establish causal relationships between X and Y
Q59. A correlation coefficient (r) close to +1 indicates:
A. No relationship
B. Strong positive relationship
C. Strong negative relationship
D. Random variation
✅ Answer: B. Strong positive relationship
Q60. The p-value in hypothesis testing measures:
A. The risk of Type II error
B. The probability of observing data given the null hypothesis
C. The variation between means
D. Confidence interval width
✅ Answer: B. The probability of observing data given the null hypothesis
Q61. A low p-value (typically < 0.05) indicates:
A. Strong evidence against the null hypothesis
B. The null hypothesis is accepted
C. Random error is high
D. The model is inconclusive
✅ Answer: A. Strong evidence against the null hypothesis
Q62. In hypothesis testing, a Type I error means:
A. Rejecting a true null hypothesis
B. Failing to reject a false null hypothesis
C. Accepting the alternative incorrectly
D. Confusing alpha with beta risk
✅ Answer: A. Rejecting a true null hypothesis
Q63. Alpha (α) in Six Sigma analysis typically represents:
A. Process capability
B. Probability of Type I error
C. Process mean
D. Confidence level
✅ Answer: B. Probability of Type I error
Q64. Beta (β) risk in hypothesis testing is:
A. Risk of detecting false positives
B. Risk of missing a real effect (Type II error)
C. Risk of overcontrol
D. Chance of recalibration
✅ Answer: B. Risk of missing a real effect (Type II error)
Q65. The “power” of a test is defined as:
A. 1 - α
B. 1 - β
C. α + β
D. σ² / μ
✅ Answer: B. 1 - β
Q66. Which tool visually represents process flow to identify bottlenecks?
A. Pareto chart
B. Process Flow Diagram
C. Histogram
D. Scatter Plot
✅ Answer: B. Process Flow Diagram
Q67. A Histogram is primarily used to:
A. Compare proportions
B. Display frequency distribution of data
C. Evaluate process steps
D. Create stratified samples
✅ Answer: B. Display frequency distribution of data
Q68. A Control Chart helps to:
A. Assess measurement bias
B. Distinguish between common and special cause variation
C. Calculate cost of poor quality
D. Identify customer VOC
✅ Answer: B. Distinguish between common and special cause variation
Q69. If points fall outside the control limits, it indicates:
A. Common cause variation
B. Special cause variation
C. Stable process
D. High capability
✅ Answer: B. Special cause variation
Q70. The Center Line in a control chart represents:
A. Mean or expected value of the process
B. Customer tolerance
C. Process upper limit
D. Sigma level
✅ Answer: A. Mean or expected value of the process
Q71. The “Western Electric Rules” are used to:
A. Determine process cost
B. Detect patterns in control charts
C. Evaluate process capability
D. Adjust sampling size
✅ Answer: B. Detect patterns in control charts
Q72. A process is considered “capable” when:
A. Cp and Cpk ≥ 1.33
B. Cp = 0.5
C. Sigma < 2
D. Yield is 50%
✅ Answer: A. Cp and Cpk ≥ 1.33
Q73. Cp measures:
A. Process centering
B. Process spread relative to tolerance
C. Operator performance
D. VOC satisfaction
✅ Answer: B. Process spread relative to tolerance
Q74. Cpk measures:
A. Variation only
B. Process centering and spread
C. Process mean
D. Sampling error
✅ Answer: B. Process centering and spread
Q75. When Cp > Cpk, the process is:
A. Perfectly centered
B. Off-center but consistent
C. Completely out of control
D. Defective
✅ Answer: B. Off-center but consistent
Q76. A Cp value less than 1 implies:
A. Process fits comfortably within specifications
B. Process variation exceeds tolerance limits
C. Process has zero defects
D. Process is at Six Sigma level
✅ Answer: B. Process variation exceeds tolerance limits
Q77. The Z-score measures:
A. Sigma level in standard deviations
B. Mean of all defects
C. VOC gap
D. Process yield percentage
✅ Answer: A. Sigma level in standard deviations
Q78. A 3 Sigma process corresponds roughly to a defect rate of:
A. 0.002%
B. 6.7%
C. 50%
D. 0.34%
✅ Answer: B. 6.7%
Q79. The higher the Sigma level, the:
A. Greater the variation
B. Lower the defect rate
C. Higher the tolerance
D. Lower the yield
✅ Answer: B. Lower the defect rate
Q80. Cost of Poor Quality (COPQ) typically includes:
A. Only external failures
B. Prevention, appraisal, internal, and external costs
C. Training and audit costs only
D. Supplier inspection costs
✅ Answer: B. Prevention, appraisal, internal, and external costs
Q81. Which cost category represents defects caught before reaching the customer?
A. External failure
B. Internal failure
C. Appraisal
D. Prevention
✅ Answer: B. Internal failure
Q82. Which COPQ component includes warranty claims?
A. Internal failure
B. External failure
C. Appraisal
D. Prevention
✅ Answer: B. External failure
Q83. The “Improve” phase aims to:
A. Identify variation
B. Implement validated solutions
C. Measure baseline performance
D. Calculate capability indices
✅ Answer: B. Implement validated solutions
Q84. A DOE (Design of Experiments) helps in:
A. Collecting random feedback
B. Testing multiple variables simultaneously
C. Creating project charters
D. Monitoring project budgets
✅ Answer: B. Testing multiple variables simultaneously
Q85. The Control phase ensures:
A. Problems are revisited regularly
B. Sustained performance improvements
C. Statistical analysis is completed
D. Team disbanding after success
✅ Answer: B. Sustained performance improvements
Q86. Control Plans primarily contain:
A. VOC data
B. Project budgets
C. Standard operating instructions and metrics
D. Gantt charts
✅ Answer: C. Standard operating instructions and metrics
Q87. A run chart differs from a control chart because:
A. It lacks control limits
B. It shows Sigma levels
C. It calculates Cp
D. It includes DPMO
✅ Answer: A. It lacks control limits
Q88. The “standard deviation” represents:
A. Average defect count
B. Dispersion of data around the mean
C. Range of process outputs
D. Customer specification gap
✅ Answer: B. Dispersion of data around the mean
Q89. Reducing standard deviation directly leads to:
A. Higher variation
B. Improved process capability
C. Lower yield
D. Higher costs
✅ Answer: B. Improved process capability
Q90. A normal distribution has approximately what percentage of data within ±1σ?
A. 68%
B. 95%
C. 99.7%
D. 50%
✅ Answer: A. 68%
Q91. Approximately 99.7% of data in a normal distribution lies within:
A. ±1σ
B. ±2σ
C. ±3σ
D. ±6σ
✅ Answer: C. ±3σ
Q92. Which statistical tool checks normality of data?
A. Histogram
B. Normal Probability Plot
C. Fishbone Diagram
D. Pareto Chart
✅ Answer: B. Normal Probability Plot
Q93. Sampling error decreases when:
A. Sample size increases
B. Process variation increases
C. Measurement frequency reduces
D. Operator bias increases
✅ Answer: A. Sample size increases
Q94. Stratified sampling helps in:
A. Randomizing variation
B. Ensuring representation across categories
C. Eliminating sampling bias completely
D. Controlling measurement system error
✅ Answer: B. Ensuring representation across categories
Q95. The primary deliverable of the Measure phase is:
A. Baseline performance metrics
B. Future process map
C. VOC summary
D. Project charter
✅ Answer: A. Baseline performance metrics
Q96. Process Capability Analysis compares:
A. Actual variation vs specification limits
B. VOC vs VOB
C. Alpha vs Beta
D. CTQ vs Y
✅ Answer: A. Actual variation vs specification limits
Q97. When a process is stable but not capable, it means:
A. It’s unpredictable
B. It’s consistent but outside customer limits
C. It’s under statistical control
D. It has no measurement error
✅ Answer: B. It’s consistent but outside customer limits
Q98. Control charts are applicable when:
A. The process is unstable
B. Data collection is manual
C. There is continuous monitoring of a stable process
D. Only attribute data is available
✅ Answer: C. There is continuous monitoring of a stable process
Q99. Attribute Control Charts are used for:
A. Continuous data
B. Count or classification data
C. Regression analysis
D. DOE results
✅ Answer: B. Count or classification data
Q100. Variable Control Charts include:
A. p-chart and np-chart
B. X-bar and R chart
C. c-chart and u-chart
D. Run chart
✅ Answer: B. X-bar and R chart
Q101. A p-chart is used to track:
A. Proportion of defectives
B. Number of defects per unit
C. Process mean
D. Variation of continuous data
✅ Answer: A. Proportion of defectives
Q102. A c-chart monitors:
A. Count of defects per unit
B. Defective percentage
C. Sigma level
D. Mean variation
✅ Answer: A. Count of defects per unit
Q103. Control limits are calculated using:
A. Standard deviation
B. Mean difference
C. Cp value
D. Sigma level alone
✅ Answer: A. Standard deviation
Q104. Which phase ensures “lessons learned” documentation?
A. Define
B. Improve
C. Control
D. Measure
✅ Answer: C. Control
Q105. In Six Sigma, short-term variation is often:
A. Greater than long-term
B. Less than long-term
C. Equal to long-term
D. Irrelevant
✅ Answer: B. Less than long-term
Q106. The “1.5 Sigma shift” accounts for:
A. Natural long-term process drift
B. Measurement bias
C. Operator turnover
D. Cost inflation
✅ Answer: A. Natural long-term process drift
Q107. Which statistical tool is used to check equality of means?
A. Chi-square test
B. ANOVA
C. Regression analysis
D. Z-test
✅ Answer: B. ANOVA
Q108. Which test compares two population means when variance is unknown?
A. Z-test
B. t-test
C. F-test
D. Chi-square test
✅ Answer: B. t-test
Q109. Confidence intervals estimate:
A. A range where the true population parameter lies
B. The exact population mean
C. Process defects
D. Alpha risk
✅ Answer: A. A range where the true population parameter lies
Q110. A Control Chart showing no points outside limits and no patterns indicates:
A. Unstable process
B. Capable and in-control process
C. Out-of-spec process
D. Overadjusted process
✅ Answer: B. Capable and in-control process
Six Sigma MCQs, DMAIC quiz, Process Capability questions, Measure phase Six Sigma, MSA, Cp Cpk quiz, Six Sigma belts roles, DPMO, process variation
