Lean Six Sigma Yellow Belt Certification Lean Concepts and Waste 4 — Questions and Answers
Question 1: What does 'Muri' mean in the context of the three types of waste in Lean?
- Unevenness in workload
- Overburden on people or machines (Correct answer)
- Any physical waste material
- Defective products
Correct answer: Overburden on people or machines
Muri refers to overburden — pushing workers or equipment beyond their natural capacity, leading to breakdowns and errors.
Question 2: Which waste category does rework of defective products fall into?
- Waiting
- Defects
- Extra processing
- Both defects and extra processing (Correct answer)
Correct answer: Both defects and extra processing
Rework represents defects (the item failed) and extra processing (additional work to correct the failure), capturing both waste types.
Question 3: A Lean practitioner performs a 'Gemba walk.' What is the primary purpose of this activity?
- To review financial reports
- To go to the actual workplace and observe real processes to identify waste (Correct answer)
- To conduct employee performance reviews
- To update value stream maps in the office
Correct answer: To go to the actual workplace and observe real processes to identify waste
A Gemba walk involves going to where work is done to observe processes firsthand and identify waste, problems, and improvement opportunities.
Question 4: Takt time is calculated as which of the following?
- Total production time divided by number of defects
- Available production time divided by customer demand rate (Correct answer)
- Cycle time multiplied by number of workers
- Total inventory divided by daily usage
Correct answer: Available production time divided by customer demand rate
Takt time = available production time / customer demand, setting the pace at which products must be completed to meet demand.
Question 5: Which of the following best describes a 'value-added' activity in Lean?
- Any activity performed by a skilled worker
- An activity that transforms the product in a way the customer values and is willing to pay for (Correct answer)
- Any activity required by company policy
- An activity that reduces employee effort
Correct answer: An activity that transforms the product in a way the customer values and is willing to pay for
A value-added activity physically transforms the product or service in a way the customer recognizes and would pay for.
Question 6: An inspection step at the end of a production line that catches defects is considered which type of activity?
- Value-added
- Business-value-added (necessary non-value-added) (Correct answer)
- Pure waste
- Continuous improvement
Correct answer: Business-value-added (necessary non-value-added)
Inspection is a necessary non-value-added activity — it doesn't transform the product but may be required to ensure quality until root causes are eliminated.
Question 7: In a Lean office environment, which of the following would be classified as a 'defect' waste?
- A report printed on both sides of paper
- An invoice sent with incorrect billing information requiring correction (Correct answer)
- A meeting held with a detailed agenda
- Digital filing of documents instead of paper
Correct answer: An invoice sent with incorrect billing information requiring correction
An incorrect invoice is a defect in a service process — it requires rework, delays payment, and damages customer trust.
Lean Six Sigma Yellow Belt Certification Lean Concepts and Waste 4
What does 'Muri' mean in the context of the three types of waste in Lean?