Measurement systems analysis evaluates a gauge, its fixtures, software, operators and procedure as one system. A full MSA covers bias, linearity across the range, stability over time, and repeatability and reproducibility, plus attribute agreement studies for pass/fail judgments. Automotive and fab quality systems require an MSA before data from a gauge can feed SPC, capability studies or product release.
New thickness tool can't go on the SPC plan until the MSA is signed off: bias, linearity and a gauge R&R.
Also heard as
- measurement systems analysis
- measurement system evaluation
Related terms
Gauge R&R
Study that measures how much observed variation comes from the measurement system's repeatability and reproducibility.
Bias
Systematic offset between the average of repeated measurements and the true or reference value.
P/T ratio
Precision-to-tolerance ratio: measurement system spread as a fraction of the specification width.
Tool matching
Making several tools or chambers that run the same step produce the same results on the same material.