Quality measurement in manufacturing MCQs With Answer

Introduction

Quality measurement in manufacturing is a critical area for M.Pharm students who will oversee production of safe, effective pharmaceutical products. This blog provides focused multiple-choice questions (MCQs) that probe key concepts such as process capability indices (Cp, Cpk, Pp, Ppk), statistical process control (SPC) charts, measurement system analysis (Gage R&R), sampling and acceptance criteria (AQL, LTPD), calibration and measurement uncertainty, and performance metrics like OEE and DPMO. Questions are designed to deepen understanding of how measurement and statistical tools are applied in pharmaceutical manufacturing to ensure compliance, control variability, and maintain product quality. Each question includes clear options and the correct answer to support exam preparation and practical application.

Q1. What does the process capability index Cp primarily measure in a manufacturing process?

• The centering of the process mean relative to specification limits
• The ratio of specification width to process variability
• The overall long-term process performance including shift and drift
• The probability of a nonconforming unit

Correct Answer: The ratio of specification width to process variability

Q2. Which index accounts for both process spread and how well the process is centered within specifications?

• Cp
• Pp
• Cpk
• Ppk

Correct Answer: Cpk

Q3. In a Gage R&R study, what does repeatability refer to?

• Variation between different operators measuring the same part
• Variation due to measurement equipment when the same operator measures repeatedly
• The systematic bias between a measured value and true value
• Variation between parts being measured

Correct Answer: Variation due to measurement equipment when the same operator measures repeatedly

Q4. Which control chart is most appropriate for monitoring the average weight of tablet subgroups in production?

• p-chart
• X-bar chart
• c-chart
• np-chart

Correct Answer: X-bar chart

Q5. How is DPMO (defects per million opportunities) calculated?

• (Number of defects / Number of units inspected) × 1,000,000
• (Number of defects / (Number of units × Opportunities per unit)) × 1,000,000
• (Number of nonconforming units / Number of units inspected) × 1,000
• (Number of defects / Total production batches) × 1,000,000

Correct Answer: (Number of defects / (Number of units × Opportunities per unit)) × 1,000,000

Q6. Which statement best distinguishes control limits from specification limits?

• Control limits are set by regulatory authorities; specification limits are statistical
• Control limits reflect process variability; specification limits reflect customer or regulatory requirements
• Control limits always lie outside specification limits
• Specification limits are used only for sampling plans, control limits only for calibration

Correct Answer: Control limits reflect process variability; specification limits reflect customer or regulatory requirements

Q7. Which sampling plan term describes the maximum percent defective that is considered acceptable as a process average?

• LTPD
• AQL
• Type I error
• Producer risk

Correct Answer: AQL

Q8. What is the principal purpose of a measurement system analysis (MSA) in pharmaceutical manufacturing?

• To calculate process capability indices
• To assess the reliability and suitability of the measurement system
• To set specification limits for new products
• To determine batch release criteria

Correct Answer: To assess the reliability and suitability of the measurement system

Q9. For a normally distributed process, how is Cp computed?

• (USL – LSL) / (6 × σ)
• (USL – LSL) / (3 × σ)
• (USL – mean) / (3 × σ)
• mean / σ

Correct Answer: (USL – LSL) / (6 × σ)

Q10. What does a Ppk index lower than Cp typically indicate about a process?

• The process is short-term variable but well-centered
• The process mean is shifted relative to specification limits
• The sample size used was too large
• Measurement system error is negligible

Correct Answer: The process mean is shifted relative to specification limits

Q11. Which of the following is an appropriate response when an X-bar control chart shows a point outside the control limits?

• Immediately change the specification limits
• Investigate for special cause variation and take corrective action if needed
• Ignore it if Cp is greater than 1
• Replace the entire production line

Correct Answer: Investigate for special cause variation and take corrective action if needed

Q12. In SPC, what is meant by common cause variation?

• Variation caused by specific assignable factors that are intermittent
• Inherent variation within a stable process that is predictable
• Variation due to measurement bias only
• Variation that always leads to batch rejection in pharma

Correct Answer: Inherent variation within a stable process that is predictable

Q13. What is Overall Equipment Effectiveness (OEE) used to measure?

• The measurement uncertainty of analytical instruments
• The combined performance of availability, performance rate, and quality rate of equipment
• The number of defects per million opportunities
• The process capability for tablet hardness

Correct Answer: The combined performance of availability, performance rate, and quality rate of equipment

Q14. Which metric quantifies the proportion of variation due to operators rather than the measurement device in Gage R&R?

• Repeatability
• Reproducibility
• Bias
• Linearity

Correct Answer: Reproducibility

Q15. Which statement correctly describes LTPD (Lot Tolerance Percent Defective)?

• It is the maximum defect rate producers will tolerate
• It is the defect level that the consumer considers unacceptable for a lot
• It equals the AQL for all sampling plans
• It measures variation within subgroup samples

Correct Answer: It is the defect level that the consumer considers unacceptable for a lot

Q16. What does a high Gage R&R % of total variation imply for process measurement?

• The measurement system contributes little to observed variation
• The measurement system is a major source of variation and needs improvement
• The process capability indices will always be high
• It indicates excellent reproducibility

Correct Answer: The measurement system is a major source of variation and needs improvement

Q17. When expressing measurement uncertainty, what does an expanded uncertainty with coverage factor k=2 commonly represent?

• Approximately 50% confidence interval
• Approximately 95% confidence interval
• Exact value of the measurand without any uncertainty
• One standard deviation of the measurement

Correct Answer: Approximately 95% confidence interval

Q18. Which control chart is most suitable for monitoring the number of impurities (counts) per sample when occurrences are rare and sample size is constant?

• p-chart
• c-chart
• R-chart
• X-bar chart

Correct Answer: c-chart

Q19. Which action improves Ppk without changing process spread?

• Reducing measurement system variance
• Recentering the mean closer to the target
• Increasing subgroup sample size
• Changing specification limits

Correct Answer: Recentering the mean closer to the target

Q20. In acceptance sampling, what does producer’s risk (alpha) represent?

• The risk of accepting a bad lot
• The risk of rejecting a good lot
• The long-term process capability
• The measurement system repeatability

Correct Answer: The risk of rejecting a good lot

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