Lean Six Sigma Yellow Belt Certification Lean Six Sigma Yellow Belt The Measure Phase 1 — Questions and Answers
Question 1: Which of the following is an example of continuous data collected during the Measure phase?
- Number of defective units rejected per shift
- Customer satisfaction score on a 1-to-5 scale
- Cycle time measured in seconds for each transaction (Correct answer)
- Count of billing errors per invoice
Correct answer: Cycle time measured in seconds for each transaction
Continuous data can take any measurable value within a range (e.g., time, temperature, weight). Cycle time in seconds is measured on a continuous scale. The other options represent discrete (counted) data, which can only take whole-number values.
Question 2: What does a Cpk value of less than 1.0 indicate about a process?
- The process is highly capable and consistently within spec
- The process is centered perfectly between both specification limits
- The process is not capable and is producing output outside specification limits (Correct answer)
- The process has zero variation and requires no further monitoring
Correct answer: The process is not capable and is producing output outside specification limits
Cpk measures how well a process fits within its specification limits while accounting for centering. A Cpk below 1.0 means the process spread extends beyond at least one specification limit, resulting in defective output. A Cpk of 1.33 or higher is the common minimum threshold for a capable process.
Question 3: Why are operational definitions essential to establish before collecting data in the Measure phase?
- They identify the root cause of the problem being studied
- They ensure everyone measures the same thing in the same way, producing consistent data (Correct answer)
- They set the budget and timeline for the measurement system analysis
- They replace the need for a Gage R&R study
Correct answer: They ensure everyone measures the same thing in the same way, producing consistent data
Operational definitions provide a precise, unambiguous description of what is being measured and exactly how to measure it. Without them, different collectors may interpret and record data differently, making the dataset unreliable and comparisons meaningless.
Question 4: What is the main purpose of establishing a process baseline during the Measure phase?
- To develop corrective actions that will be implemented immediately
- To document current process performance so improvements can be quantified later (Correct answer)
- To identify which team members are responsible for defects
- To create the future-state value stream map
Correct answer: To document current process performance so improvements can be quantified later
A baseline captures the current level of process performance—such as defect rate, cycle time, or sigma level—before any changes are made. It serves as a benchmark so the team can objectively measure how much improvement the Improve phase actually delivered.
Question 5: In a Gage Repeatability and Reproducibility (Gage R&R) study, what does 'reproducibility' specifically measure?
- The variation seen when one operator measures the same part multiple times
- The variation that occurs when different operators measure the same part with the same gage (Correct answer)
- The total natural variation within the manufacturing process itself
- The accuracy of the measurement device compared to a certified reference standard
Correct answer: The variation that occurs when different operators measure the same part with the same gage
Reproducibility captures operator-to-operator variation—how much results differ when multiple people use the same instrument on the same part. Repeatability, by contrast, captures within-operator variation (one person, same part, multiple trials). Both components together reveal whether the measurement system is trustworthy.
Question 6: What is the primary reason for organizing data into rational subgroups when constructing a control chart during the Measure phase?
- To reduce the total number of samples required and lower collection cost
- To group data so within-subgroup variation reflects only common cause, making special cause shifts visible between subgroups (Correct answer)
- To ensure all measurements are taken at the same time of day to avoid scheduling bias
- To automatically remove outliers before plotting data on the chart
Correct answer: To group data so within-subgroup variation reflects only common cause, making special cause shifts visible between subgroups
Rational subgroups are formed so that items within each subgroup were produced under essentially the same conditions, meaning within-subgroup variation is attributable only to common (random) causes. Any special cause variation then shows up as unusual differences between subgroups, making the control chart far more sensitive to detecting real process shifts.
Lean Six Sigma Yellow Belt Certification Lean Six Sigma Yellow Belt The Measure Phase 1
Which of the following is an example of continuous data collected during the Measure phase?