Measurement System Analysis Flashcards
7 cards from real Certified Six Sigma Black Belt Exam practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Measurement System Analysis flashcards as text
What is the recommended minimum number of replicates per part-operator combination in a standard crossed Gage R&R study?
Answer: 2
AIAG MSA guidelines recommend at least 2 replicates per part-operator combination to estimate repeatability, with 3 replicates providing better estimates.
A Black Belt is analyzing a Gage R&R study where repeatability variance = 0.04 and reproducibility variance = 0.01. What percentage of R&R is due to repeatability?
Answer: 80%
Repeatability / (Repeatability + Reproducibility) = 0.04 / (0.04 + 0.01) = 0.04 / 0.05 = 80%.
Which of the following MSA components assesses whether a gage reads differently when the same part is measured from high to low versus low to high values?
Answer: Hysteresis
Hysteresis is the difference in readings when a measurement is approached from opposite directions, common in mechanical and pressure-sensing instruments.
In MSA, 'expanded uncertainty' as defined in ISO/IEC 17025 is expressed as the measurement result ± U. The coverage factor k=2 corresponds approximately to which confidence level?
Answer: 95%
A coverage factor of k=2 corresponds to approximately 95% confidence under a normal distribution, widely used in metrology laboratory reports.
A process engineer wants to use a measurement system to set statistical process control (SPC) chart limits. Which MSA outcome most directly impacts the reliability of those control limits?
Answer: Gage R&R %Study Variation relative to process variation
Control chart limits are based on process variation; if gage variation is a large fraction of total variation, the control limits will be inflated and the chart will lose sensitivity to real process shifts.
In a Gage R&R study, a master appraiser measures 10 parts 3 times each. The average range across all parts is 0.015. The d2* value for 3 replicates and 10 parts is 1.693. What is the estimated repeatability standard deviation?
Answer: 0.00886
Repeatability σ = R̄ / d2* = 0.015 / 1.693 ≈ 0.00886.
Which of the following best explains why a measurement system can have low %R&R yet still be inadequate for the process?
Answer: The process variation is so large that even a poor gage appears acceptable relative to it
If process variation is very large (wide spread), even a mediocre gage will show a low %R&R because the denominator (process spread) is large — the gage may still be inadequate for detecting small shifts.