Lean Six Sigma Yellow Belt Certification Measure Phase Tools 3 — Questions and Answers
Question 1: In a Gage R&R study, a high percentage of variation attributed to 'Part-to-Part' variation is:
- Undesirable because it indicates the gauge is unreliable
- Desirable because it shows the measurement system can distinguish between parts (Correct answer)
- Irrelevant to the measurement system analysis
- An indicator that operators need retraining
Correct answer: Desirable because it shows the measurement system can distinguish between parts
High part-to-part variation relative to gauge variation means the measurement system is sensitive enough to detect real differences between parts.
Question 2: A SIPOC diagram is primarily used during the Measure phase to:
- Identify the root cause of the primary defect
- Provide a high-level view of the process and its key inputs and outputs (Correct answer)
- Calculate the sigma level of the current process
- Prioritize improvement solutions by cost and impact
Correct answer: Provide a high-level view of the process and its key inputs and outputs
SIPOC maps Suppliers, Inputs, Process, Outputs, and Customers at a macro level to scope the process being measured.
Question 3: Which control chart is most appropriate for monitoring the proportion of defective units in a process with variable subgroup sizes?
- X-bar and R chart
- p-chart (Correct answer)
- c-chart
- Individuals (I) chart
Correct answer: p-chart
The p-chart is designed for attribute data tracking the proportion defective and accommodates varying subgroup sizes.
Question 4: What is the primary purpose of establishing operational definitions before data collection?
- To reduce the cost of collecting data
- To ensure everyone collects and interprets data consistently (Correct answer)
- To determine which statistical tool to use for analysis
- To identify the key process input variables automatically
Correct answer: To ensure everyone collects and interprets data consistently
Operational definitions eliminate ambiguity so all collectors measure the same characteristic in the same way, ensuring data integrity.
Question 5: In the context of Lean Six Sigma, 'Takt time' is calculated as:
- Total defects divided by total opportunities
- Available production time divided by customer demand rate (Correct answer)
- Cycle time minus wait time
- Process lead time divided by value-added time
Correct answer: Available production time divided by customer demand rate
Takt time sets the pace of production by dividing available work time by the rate of customer demand.
Question 6: A scatter diagram showing a strong positive correlation between two variables means:
- One variable causes the other to change
- As one variable increases, the other tends to increase as well (Correct answer)
- The two variables are perfectly correlated with no exceptions
- The relationship is inverse and proportional
Correct answer: As one variable increases, the other tends to increase as well
A positive correlation means the two variables move in the same direction, though correlation alone does not imply causation.
Question 7: Which tool is used to visually separate the 'vital few' causes from the 'trivial many' in defect analysis?
- Histogram
- Pareto chart (Correct answer)
- Box plot
- Control chart
Correct answer: Pareto chart
A Pareto chart ranks defects or causes by frequency or impact, highlighting the few categories responsible for most of the problem.
Lean Six Sigma Yellow Belt Certification Measure Phase Tools 3
In a Gage R&R study, a high percentage of variation attributed to 'Part-to-Part' variation is: