OIT Quality Assurance and Improvement 3 — Questions and Answers
Question 1: Which PDCA cycle step involves analyzing data collected during a process change to see if the desired improvement occurred?
- Plan
- Do
- Check (Correct answer)
- Act
Correct answer: Check
The 'Check' step of the PDCA cycle involves studying the results of the change to determine whether it achieved the intended improvement.
Question 2: A defect rate of 3.4 defects per million opportunities corresponds to which Sigma level?
- 3 Sigma
- 4 Sigma
- 5 Sigma
- 6 Sigma (Correct answer)
Correct answer: 6 Sigma
Six Sigma processes achieve a quality level of 3.4 defects per million opportunities (DPMO), representing near-perfect process performance.
Question 3: What does 'poka-yoke' refer to in manufacturing quality?
- A Japanese term for continuous improvement
- An error-proofing mechanism that prevents or detects defects at their source (Correct answer)
- A quality audit checklist
- A method for sorting and organizing the workplace
Correct answer: An error-proofing mechanism that prevents or detects defects at their source
Poka-yoke refers to mistake-proofing devices or methods designed to prevent errors from occurring or to immediately detect them when they do.
Question 4: Which type of quality cost involves inspecting, testing, and auditing to ensure products meet standards?
- Prevention costs
- Appraisal costs (Correct answer)
- Internal failure costs
- External failure costs
Correct answer: Appraisal costs
Appraisal costs are incurred to detect nonconformance through inspection, testing, and audits before products reach the customer.
Question 5: In a control chart, what do the Upper Control Limit (UCL) and Lower Control Limit (LCL) represent?
- Customer specification limits
- The maximum and minimum allowable tolerances
- The boundaries of expected natural process variation (±3 sigma) (Correct answer)
- The target value plus or minus 10%
Correct answer: The boundaries of expected natural process variation (±3 sigma)
UCL and LCL on a control chart represent ±3 standard deviations from the process mean, defining the range of expected natural (common cause) variation.
Question 6: Which lean quality tool focuses on organizing the workplace into five categories: Sort, Set in order, Shine, Standardize, and Sustain?
- Kanban
- 5S (Correct answer)
- Kaizen
- SMED
Correct answer: 5S
5S is a workplace organization methodology that uses five steps to create a clean, organized, and efficient environment, reducing waste and errors.
Question 7: When a quality characteristic is measured on a continuous scale (e.g., length, weight, temperature), which type of control chart is most appropriate?
- p-chart
- c-chart
- X-bar and R chart (Correct answer)
- np-chart
Correct answer: X-bar and R chart
The X-bar and R chart monitors the mean and range of continuous (variable) measurement data, making it appropriate for dimensions, weights, and temperatures.
OIT Quality Assurance and Improvement 3
Which PDCA cycle step involves analyzing data collected during a process change to see if the desired improvement occurred?