Supply Chain Management Quality Control 2 — Questions and Answers
Question 1: Which sampling plan standard is most commonly used in US supply chain acceptance sampling?
- ANSI/ASQ Z1.4 (Correct answer)
- ISO 9001
- MIL-STD-1916
- ASTM E2234
Correct answer: ANSI/ASQ Z1.4
ANSI/ASQ Z1.4 is the primary US standard for attribute acceptance sampling by lot.
Question 2: A supplier's process has a Cpk of 0.85. What does this indicate?
- The process is highly capable
- The process is centered but marginally capable
- The process is not capable and likely producing defects (Correct answer)
- The process needs more data to evaluate
Correct answer: The process is not capable and likely producing defects
A Cpk below 1.0 indicates the process is not capable and is likely producing out-of-spec parts.
Question 3: In a control chart, what does a 'run of 8 consecutive points on one side of the centerline' indicate?
- Normal process variation
- A special cause of variation (Correct answer)
- An acceptable trend
- Random sampling error
Correct answer: A special cause of variation
Eight consecutive points on one side of the centerline is a Western Electric rule violation signaling a special cause.
Question 4: What is the primary purpose of a Gauge R&R study in supply chain quality?
- To evaluate supplier pricing
- To assess measurement system variation vs. part variation (Correct answer)
- To determine acceptable defect rates
- To calibrate production equipment
Correct answer: To assess measurement system variation vs. part variation
Gauge R&R quantifies how much of observed variation comes from the measurement system versus the actual parts.
Question 5: Which quality tool is used to stratify defects by category to identify the most significant causes?
- Control chart
- Scatter diagram
- Pareto chart (Correct answer)
- Histogram
Correct answer: Pareto chart
A Pareto chart ranks defect categories by frequency to highlight the vital few causes (80/20 rule).
Question 6: What does 'AQL' stand for in supply chain quality inspection?
- Average Quality Limit
- Acceptable Quality Level (Correct answer)
- Audit Quality Log
- Adjusted Quality Lot
Correct answer: Acceptable Quality Level
AQL (Acceptable Quality Level) defines the maximum defect percentage considered acceptable for a batch.
Question 7: A company receives a shipment and finds 3% defective units, against an AQL of 1.0. What is the correct action?
- Accept the lot with a corrective action request
- Reject the lot and return it to the supplier (Correct answer)
- Sort the entire lot and accept conforming units
- Retest with a larger sample
Correct answer: Reject the lot and return it to the supplier
When actual defect rate exceeds the AQL, the standard procedure is to reject the lot per the sampling plan.
Supply Chain Management Quality Control 2
Which sampling plan standard is most commonly used in US supply chain acceptance sampling?