Lean Six Sigma Green Belt Certification Core Lean Principles 5 — Questions and Answers
Question 1: What does a 'gemba walk' involve in Lean practice?
- Reviewing process data from a conference room
- Going to the actual workplace to observe the real process firsthand (Correct answer)
- Conducting employee interviews about process problems
- Analyzing historical defect reports at a management meeting
Correct answer: Going to the actual workplace to observe the real process firsthand
Gemba (Japanese for 'the real place') walks involve leaders and practitioners going to where value is created to observe, learn, and identify waste directly.
Question 2: Which of the following scenarios best represents 'defects' waste in a service industry context?
- A call center agent waiting for a slow computer system to load
- An insurance claim processed incorrectly that must be reworked and resubmitted (Correct answer)
- A report printed but never reviewed by management
- Excess staff scheduled on a slow business day
Correct answer: An insurance claim processed incorrectly that must be reworked and resubmitted
Defects waste in services includes errors such as incorrect data entry, wrong information provided to customers, or any output that fails to meet requirements and requires rework.
Question 3: What is the relationship between cycle time and takt time that indicates a process is balanced correctly?
- Cycle time should be significantly greater than takt time
- Cycle time should approximately equal takt time (Correct answer)
- Takt time should be set to the fastest achievable cycle time
- Cycle time and takt time are unrelated metrics
Correct answer: Cycle time should approximately equal takt time
When cycle time equals takt time, the process produces exactly what customers demand without creating overproduction or causing a backlog.
Question 4: In Lean, which step of the 5S methodology involves removing all unneeded items from the work area?
- Set in Order (Seiton)
- Shine (Seiso)
- Sort (Seiri) (Correct answer)
- Standardize (Seiketsu)
Correct answer: Sort (Seiri)
Sort (Seiri) is the first S, requiring teams to identify and remove everything not needed for current work, leaving only what is necessary.
Question 5: A manufacturer implements one-piece flow instead of batch processing. Which primary Lean benefit does this most directly achieve?
- Reduced labor costs through headcount reduction
- Shorter lead times and faster detection of quality defects (Correct answer)
- Higher machine utilization rates
- Simplified inventory accounting
Correct answer: Shorter lead times and faster detection of quality defects
One-piece flow reduces work-in-process inventory and exposes defects immediately at the next step rather than discovering them after a large batch has been completed.
Question 6: Which Lean concept describes building quality into the process so that defects are caught at their source rather than detected later?
- Jidoka (autonomation) (Correct answer)
- Heijunka (leveling)
- Hoshin Kanri (policy deployment)
- Hanedashi (auto-eject)
Correct answer: Jidoka (autonomation)
Jidoka gives machines or workers the authority and ability to stop production when a defect or abnormality is detected, preventing defects from passing downstream.
Question 7: In Lean, 'unused talent' (sometimes called the 9th waste) refers to which failure?
- Purchasing equipment with capabilities beyond current process needs
- Failing to use the skills, knowledge, and ideas of employees (Correct answer)
- Hiring workers without the required technical certifications
- Over-investing in employee training programs
Correct answer: Failing to use the skills, knowledge, and ideas of employees
Unused talent waste occurs when organizations fail to engage employees' creativity, experience, and problem-solving abilities in improvement activities.
Lean Six Sigma Green Belt Certification Core Lean Principles 5
What does a 'gemba walk' involve in Lean practice?