Automotive
MSA: Measurement System Analysis
Before trusting data, verify the measurement system. MSA quantifies how much of observed variation comes from measuring.
Reference noteThis page is an independent plain-language summary written by QUALITAS TR. It does not reproduce the standard. Always work from the current official edition, available from AIAG, the Automotive Industry Action Group (FMEA jointly with VDA) (official page). QUALITAS TR supports organisations against this standard; it does not certify them.
01Purpose
MSA evaluates the statistical properties of measurement systems to determine whether they are adequate for their intended use, such as product acceptance or process control.
02Scope
Applies to variable and attribute gauges used for characteristics in control plans, especially special characteristics.
03Main requirements
- Bias and linearity
- Stability over time
- Repeatability and reproducibility (gauge R&R)
- Number of distinct categories
- Attribute agreement analysis
- Common guideline: %GRR below 10% acceptable, 10 to 30% may be acceptable depending on application, above 30% not acceptable
04Typical applications and industries
Required for PPAP and used whenever measurement data drives decisions.
05Audit and inspection considerations
- Is MSA done on the actual gauge and parts?
- Do studies cover operators who actually measure?
- Is resolution adequate for the tolerance?
06Common nonconformities
- Studies with parts not representing process variation
- Gauge resolution too coarse
- Attribute gauges never evaluated
07How QUALITAS TR can support
We evaluate measurement systems during audits and dimensional inspections.