Lean Six Sigma Green Belt Certification Lean Six Sigma Green Belt Core Lean Principles 1 — Questions and Answers
Question 1: What does 'takt time' represent in Lean methodology?
- The time required to complete one full DMAIC cycle
- The rate at which a product must be completed to meet customer demand (Correct answer)
- The average time a worker spends on non-value-added activities
- The maximum allowable defect rate in a production run
Correct answer: The rate at which a product must be completed to meet customer demand
Takt time is calculated by dividing available production time by customer demand. It sets the production rhythm needed to meet customer requirements without overproducing or underproducing.
Question 2: Which of the following best describes the purpose of a Value Stream Map (VSM)?
- To assign blame for defects to specific process steps
- To document the flow of materials and information required to deliver a product or service to the customer (Correct answer)
- To create a ranking of the most expensive wastes in a process
- To establish standard operating procedures for each workstation
Correct answer: To document the flow of materials and information required to deliver a product or service to the customer
A Value Stream Map visually depicts every step in the flow of materials and information, helping teams identify value-added versus non-value-added activities and prioritize improvement efforts.
Question 3: In the 5S Lean framework, what does the third 'S' — 'Shine' — require teams to do?
- Sort items into keep, discard, or return categories
- Establish visual standards and labels for all workstations
- Clean the work area and inspect equipment during the cleaning process (Correct answer)
- Sustain improvements through regular audits and discipline
Correct answer: Clean the work area and inspect equipment during the cleaning process
'Shine' (Seiso) goes beyond basic cleaning — teams clean the workspace while simultaneously inspecting equipment for defects, leaks, or abnormalities, turning cleaning into a form of inspection.
Question 4: Which Lean concept refers to designing a process or device so that mistakes are physically impossible or immediately obvious?
- Heijunka
- Poka-Yoke (Correct answer)
- Andon
- Hoshin Kanri
Correct answer: Poka-Yoke
Poka-Yoke (mistake-proofing) involves design mechanisms that prevent errors from occurring or make defects instantly detectable before they move to the next step, reducing reliance on operator vigilance.
Question 5: In Lean, 'Mura' refers to which type of process problem?
- Waste generated by excess inventory
- Unevenness or inconsistency in workflow and production levels (Correct answer)
- Overburdening of employees or equipment beyond their capacity
- Defects caused by poor raw material quality
Correct answer: Unevenness or inconsistency in workflow and production levels
Mura means unevenness or variability in the flow of work. When production levels fluctuate unpredictably, it creates both idle time and overburden, leading to additional waste throughout the system.
Question 6: Which Lean principle states that production should be triggered by actual customer demand rather than forecasts or schedules pushed from upstream?
- Flow
- Pull (Correct answer)
- Perfection
- Value
Correct answer: Pull
The 'Pull' principle means that work is initiated only when a downstream process or customer signals a need, preventing overproduction and aligning output directly with real demand rather than predicted demand.
Lean Six Sigma Green Belt Certification Lean Six Sigma Green Belt Core Lean Principles 1
What does 'takt time' represent in Lean methodology?