Lean Six Sigma Yellow Belt Certification Prep 5 — Questions and Answers
Question 1: Which tool is MOST appropriate for prioritizing which problems to solve when resources are limited?
- Pareto chart applying the 80/20 rule (Correct answer)
- Gage R&R study
- Control chart
- SIPOC diagram
Correct answer: Pareto chart applying the 80/20 rule
A Pareto chart identifies the 'vital few' causes responsible for the majority of defects, enabling teams to focus limited resources for maximum impact.
Question 2: A process with Cpk = 0.5 indicates:
- The process is not capable and produces many defects outside specification limits (Correct answer)
- The process is well-centered and highly capable
- The process meets minimum industry standards
- The process has zero defects
Correct answer: The process is not capable and produces many defects outside specification limits
Cpk < 1.0 means the process is not capable; Cpk = 0.5 indicates the process is significantly off-center or too variable relative to specifications.
Question 3: In the 5S methodology, what does the second 'S' (Seiton) mean?
- Set in order — arrange tools and materials for efficient access (Correct answer)
- Sort — remove unnecessary items
- Shine — clean the workspace
- Standardize — create consistent practices
Correct answer: Set in order — arrange tools and materials for efficient access
Seiton (Set in Order) means organizing remaining items so everything has a designated place, reducing search time and enabling visual management.
Question 4: A run chart shows 8 consecutive data points all above the process mean. This is an example of:
- A signal of special cause variation requiring investigation (Correct answer)
- Normal common cause variation
- Process capability improvement
- Measurement system error
Correct answer: A signal of special cause variation requiring investigation
The 'rule of eight' states that 8 or more consecutive points on one side of the center line signal a non-random pattern indicating special cause variation.
Question 5: What is the main goal of the Control phase in DMAIC?
- To sustain the improvements achieved and prevent the process from reverting to old behavior (Correct answer)
- To measure the current state of the process
- To identify which inputs most affect the output
- To define the problem and project scope
Correct answer: To sustain the improvements achieved and prevent the process from reverting to old behavior
The Control phase institutionalizes improvements through control plans, standard operating procedures, and monitoring systems to sustain gains long-term.
Question 6: Which of the following is an example of 'value-added' work in a Lean process?
- Machining a part to the customer's required specification (Correct answer)
- Waiting for material to arrive from a supplier
- Inspecting parts at the end of the line for defects
- Transporting finished goods across the facility
Correct answer: Machining a part to the customer's required specification
Value-added work transforms the product in a way the customer wants and is willing to pay for; inspection, waiting, and transport are non-value-added wastes.
Question 7: A Yellow Belt team wants to test whether a process change actually improved output quality before full implementation. The BEST approach is to:
- Run a small-scale pilot experiment and compare results to the baseline using data (Correct answer)
- Implement the change immediately across all shifts
- Ask supervisors for their opinion on whether the change worked
- Compare the new process to a competitor's process
Correct answer: Run a small-scale pilot experiment and compare results to the baseline using data
Piloting the change on a small scale and using data to compare against the baseline is the evidence-based Six Sigma approach to validating improvements before full rollout.
Lean Six Sigma Yellow Belt Certification Prep 5
Which tool is MOST appropriate for prioritizing which problems to solve when resources are limited?