Manufacturing and Production Quality Control and Assurance 1 — Questions and Answers
Question 1: What is the difference between quality control (QC) and quality assurance (QA)?
- QC is proactive; QA is reactive
- QA focuses on process prevention; QC focuses on product inspection (Correct answer)
- QC and QA are identical
- QA is only for software
Correct answer: QA focuses on process prevention; QC focuses on product inspection
QA is a process-oriented approach to prevent defects, while QC is product-oriented and involves inspecting outputs.
Question 2: What does SPC stand for in manufacturing quality?
- Standard Process Compliance
- Statistical Process Control (Correct answer)
- Supplier Performance Check
- Sequential Production Cycle
Correct answer: Statistical Process Control
Statistical Process Control uses statistical methods to monitor and control a manufacturing process.
Question 3: A control chart with points outside the upper or lower control limits indicates:
- Normal variation
- A process in statistical control
- Special cause variation requiring investigation (Correct answer)
- Acceptable product quality
Correct answer: Special cause variation requiring investigation
Points outside control limits signal special cause variation, meaning an assignable, non-random cause exists.
Question 4: What is Cpk used to measure?
- Cycle time
- Process capability relative to specification limits, accounting for centering (Correct answer)
- Cost per unit
- Capacity utilization
Correct answer: Process capability relative to specification limits, accounting for centering
Cpk measures how well a centered process fits within specification limits, with higher values indicating better capability.
Question 5: In quality management, what is a 'specification limit'?
- The natural range of process variation
- The acceptable boundary defined by engineering or the customer (Correct answer)
- The machine's maximum operating range
- A statistical control boundary
Correct answer: The acceptable boundary defined by engineering or the customer
Specification limits (USL and LSL) define the acceptable range for a product characteristic as required by the customer or design.
Question 6: What is a Pareto chart used for in quality analysis?
- Tracking production volumes over time
- Identifying the most significant defect categories by frequency or impact (Correct answer)
- Mapping process flow
- Monitoring machine temperature
Correct answer: Identifying the most significant defect categories by frequency or impact
A Pareto chart ranks defect categories to reveal which few causes account for the majority of problems (80/20 rule).
Manufacturing and Production Quality Control and Assurance 1
What is the difference between quality control (QC) and quality assurance (QA)?