LMC Quality Assurance & Improvement 2 — Questions and Answers
Question 1: A manufacturing team notices that 80% of customer complaints stem from 3 out of 15 defect types. Which Lean quality tool best supports this finding?
- Control chart
- Pareto chart (Correct answer)
- Scatter diagram
- Histogram
Correct answer: Pareto chart
A Pareto chart visualizes the 80/20 rule, identifying the vital few defect types that cause the majority of problems.
Question 2: In a Lean quality system, 'jidoka' primarily means:
- Continuous flow production
- Automation with a human touch that stops on defects (Correct answer)
- Reducing batch sizes
- Standardizing work sequences
Correct answer: Automation with a human touch that stops on defects
Jidoka empowers machines and workers to stop production immediately when a defect is detected, preventing defect propagation.
Question 3: Which metric directly measures the percentage of units that complete a process without any defect or rework on the first attempt?
- Defects Per Million Opportunities (DPMO)
- First Pass Yield (FPY) (Correct answer)
- Overall Equipment Effectiveness (OEE)
- Takt time
Correct answer: First Pass Yield (FPY)
First Pass Yield (FPY) measures the proportion of units produced correctly without rework or scrap on the first try.
Question 4: A process capability index (Cpk) of 0.85 indicates:
- The process is highly capable and centered
- The process meets Six Sigma standards
- The process is not capable and produces defects (Correct answer)
- The process has no variation
Correct answer: The process is not capable and produces defects
A Cpk below 1.0 means the process cannot consistently meet specifications, resulting in defects beyond acceptable limits.
Question 5: During a quality audit, the team finds that rework stations are located at the end of the production line. From a Lean perspective, this is problematic because:
- Rework increases takt time flexibility
- It delays defect detection, increasing waste and cost (Correct answer)
- End-of-line rework improves first pass yield
- It reduces the need for standard work
Correct answer: It delays defect detection, increasing waste and cost
Detecting and correcting defects late in the process is far more costly than catching them at the source, violating the principle of built-in quality.
Question 6: Which of the following best describes the purpose of a quality gate in a Lean process?
- To slow production and allow inspection time
- To ensure only conforming products advance to the next process step (Correct answer)
- To replace standard work documentation
- To identify the root cause of defects
Correct answer: To ensure only conforming products advance to the next process step
Quality gates act as checkpoints that prevent nonconforming items from advancing, containing defects within a process step.
Question 7: A Lean team wants to reduce variation in a welding process. Which tool would help them understand how input variables relate to output quality?
- Value stream map
- Cause-and-effect (Ishikawa) diagram (Correct answer)
- Kanban board
- 5S audit checklist
Correct answer: Cause-and-effect (Ishikawa) diagram
An Ishikawa (fishbone) diagram maps potential causes across categories like materials, methods, and machines to identify sources of output variation.
LMC Quality Assurance & Improvement 2
A manufacturing team notices that 80% of customer complaints stem from 3 out of 15 defect types.
Which Lean quality tool best supports this finding?