Mixed Deck — All Lean Six Sigma Green Belt Certification Topics Flashcards
100 cards from real Lean Six Sigma Green Belt Certification practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 20 Mixed Deck — All Lean Six Sigma Green Belt Certification Topics flashcards as text
What is the primary objective of the Analyze phase in DMAIC?
Answer: Identify and verify the root causes of the problem
The Analyze phase focuses on using data and analytical tools (such as fishbone diagrams, regression, and hypothesis testing) to identify and statistically verify the true root causes of the problem before moving to solutions.
When %Gage R&R falls in the marginal zone between 10% and 30%, the recommended course of action is to:
Answer: Evaluate the application's criticality and weigh the cost of improvement before deciding
The 10 to 30% range is a gray zone where acceptance depends on the importance of the application, the risk of measurement error, and the cost-benefit of improving the system.
Which of the following is not a typical way to identify waste?
Answer: Recycling
In Lean Six Sigma, waste (Muda) refers to any activity that consumes resources but adds no value to the customer. Common categories of waste include defects, overproduction, waiting, non-utilized talent, transportation, inventory, motion, and extra processing. While recycling is an environmental practice, it is not typically categorized as a direct type of operational waste in the context of identifying non-value-adding activities within a process.
In a hypothesis test, what does a Type II error represent?
Answer: Failing to reject a false null hypothesis
A Type II error (beta error) occurs when you fail to reject the null hypothesis even though it is actually false.
A team is analyzing the cycle time for a claims process. The data set is highly skewed to the right due to a few complex claims that took an exceptionally long time to resolve. Which measure of central tendency would provide the MOST representative value for a 'typical' claim's cycle time?
Answer: Median
The median is the middle value in a dataset and is resistant to the effects of extreme outliers. The mean (average) would be pulled higher by the few very long cycle times, giving a distorted view of the typical time. The mode is the most frequent value, which may not be representative of the center, and the range is a measure of dispersion, not central tendency.
A project team is struggling to narrow focus on what matters most to the customer. Which Define phase concept should they revisit?
Answer: Voice of the Customer
Voice of the Customer captures customer expectations and preferences to guide project priorities.
What is the purpose of a 'Poka-Yoke' device in Lean Six Sigma?
Answer: To mistake-proof a process and prevent defects from occurring or escaping
Poka-Yoke (Japanese for 'mistake-proofing') devices are designed to prevent errors from occurring or to detect them immediately so they cannot reach the next step.
Which of the following signals on an X-bar chart requires immediate investigation according to standard SPC rules?
Answer: One point beyond 3 sigma control limits
A single point beyond the 3-sigma control limits is the most fundamental out-of-control signal indicating a likely special cause that requires immediate investigation.
Which type of control chart would you use to monitor the proportion of defective items in samples of varying size?
Answer: p-chart
The p-chart is designed to track the proportion of nonconforming units and accommodates variable subgroup sizes.
In value stream mapping, what symbol typically represents a 'push' arrow between processes?
Answer: A striped or wavy push arrow
In VSM convention, a striped push arrow indicates that material is being pushed forward by the upstream process rather than pulled by downstream need.
What is the PRIMARY purpose of a response plan within a control plan?
Answer: To describe corrective actions when a process goes out of control
A response plan specifies the corrective actions operators and supervisors should take when a control chart signals an out-of-control condition.
A process capability study yields Cpk = 0.65. What does this indicate?
Answer: The process is not capable and may be off-center
A Cpk below 1.0 indicates the process is not capable of consistently producing output within specification limits, and the offset from center makes it worse than Cp alone would suggest.
Which sampling method divides the population into subgroups and then randomly samples from each subgroup?
Answer: Stratified sampling
Stratified sampling ensures representation from each subgroup by dividing the population into strata and sampling from each one.
During the Control phase, an operator notices a trend of seven consecutive points rising on an X-bar chart but all within control limits. What is the correct response?
Answer: Investigate for a special cause because a run of seven in one direction is a non-random pattern
Western Electric rules recognize that seven consecutive points trending in one direction is a non-random signal of a special cause, even if all points remain within the three-sigma control limits.
In a cause-and-effect (fishbone) diagram, the 'bones' typically represent which categories?
Answer: Man, Machine, Method, Material, Measurement, Environment
The 6M categories (Man, Machine, Method, Material, Measurement, Environment) form the main branches of a fishbone diagram to systematically explore root causes.
In a control plan, 'frequency' refers to:
Answer: How often a measurement is taken for a given CTQ or control variable
Frequency in a control plan specifies how often each characteristic must be measured (e.g., every hour, every 50 units) to detect shifts in the process in a timely manner.
In a measurement system analysis, a %Gage R&R of 28% is found. What action is most appropriate?
Answer: Investigate improvement but proceed with caution
A %Gage R&R between 10% and 30% is considered marginally acceptable; the team should work to improve the system but can proceed cautiously for some decisions.
In a Lean Six Sigma project assessment, the team is reviewing the Analyze phase outputs. Which deliverable confirms the project has correctly identified root causes before moving to Improve?
Answer: A validated fishbone with statistical evidence linking Xs to Ys
Moving from Analyze to Improve requires validated root causes where statistical analysis has confirmed the relationship between input variables (Xs) and output measures (Ys).
A Green Belt assesses a supplier's delivery performance using a p-chart. The chart shows the process is in control with an average defective rate of 4%. This means:
Answer: The process is stable and predictable at the current 4% defective rate
An in-control process on a p-chart is stable and predictable; while the 4% rate may not be acceptable, it is consistent — improvement requires a fundamental process change, not firefighting.
What statistical tool is used to test whether two or more population variances are equal?
Answer: Levene's test
Levene's test (and Bartlett's test) are used to assess the equality of variances across groups, an assumption required for many other statistical tests.