Lean Six Sigma Green Belt Certification Lean Six Sigma Green Belt Prep 1 — Questions and Answers
Question 1: Which Lean tool is used to visually map the flow of materials and information through a process from supplier to customer?
- Fishbone Diagram
- Value Stream Map (Correct answer)
- Pareto Chart
- Control Chart
Correct answer: Value Stream Map
A Value Stream Map (VSM) documents every step in the material and information flow, making waste and non-value-added steps visible so teams can design a leaner future state.
Question 2: In Lean Six Sigma, what does a process capability index (Cpk) value of less than 1.0 indicate?
- The process is well-centered within specification limits
- The process is producing defects outside specification limits (Correct answer)
- The process has zero variation
- The process meets Six Sigma quality standards
Correct answer: The process is producing defects outside specification limits
A Cpk below 1.0 means the process spread extends beyond at least one specification limit, indicating the process is incapable and producing defective output.
Question 3: Which type of waste in the Lean framework refers to unnecessary movement of people within a work area?
- Transportation
- Overproduction
- Motion (Correct answer)
- Waiting
Correct answer: Motion
Motion waste involves unnecessary physical movement by people—such as walking, bending, or reaching—that adds time and effort without adding value to the product or service.
Question 4: What is the primary output of the Measure phase in the DMAIC methodology?
- A list of potential root causes
- A baseline measure of current process performance (Correct answer)
- An implementation plan for improvements
- A validated control plan
Correct answer: A baseline measure of current process performance
The Measure phase quantifies the current state of the process by collecting data and establishing a performance baseline, which sets the benchmark against which improvements will be measured.
Question 5: In a Failure Mode and Effects Analysis (FMEA), what does the Risk Priority Number (RPN) represent?
- The number of defects per million opportunities
- The product of Severity, Occurrence, and Detection ratings (Correct answer)
- The percentage of process steps that can fail
- The cost of quality for each failure mode
Correct answer: The product of Severity, Occurrence, and Detection ratings
The RPN is calculated by multiplying the Severity (impact of the failure), Occurrence (likelihood of the failure), and Detection (ability to catch the failure before it reaches the customer) ratings, helping teams prioritize which failure modes to address first.
Question 6: Which statistical concept describes the phenomenon where sample means from any population will approach a normal distribution as sample size increases?
- Law of Large Numbers
- Central Limit Theorem (Correct answer)
- Regression to the Mean
- Standard Normal Distribution
Correct answer: Central Limit Theorem
The Central Limit Theorem states that regardless of the shape of the underlying population distribution, the distribution of sample means becomes approximately normal as the sample size grows, which is foundational to many Six Sigma statistical tests.
Lean Six Sigma Green Belt Certification Lean Six Sigma Green Belt Prep 1
Which Lean tool is used to visually map the flow of materials and information through a process from supplier to customer?