Current Edition Checked October 24, 2026
The AIAG & VDA SPC manual of 2026 now expects measurement systems to pass MSA before capability is studied.
What It Covers
How to judge whether a measurement system is good enough for its job: bias, linearity, stability, repeatability and reproducibility, and attribute agreement.
Who It Applies To
Any organization whose product decisions rely on measurements, and every gauge named in an automotive control plan.
Key Requirements
- Gauge repeatability and reproducibility (Gauge R&R) studies by the average-and-range or ANOVA method.
- Typical guidance: %GRR under 10 percent generally acceptable; 10 to 30 percent may be acceptable depending on the application; over 30 percent unacceptable.
- Number of distinct categories (ndc) of 5 or more, so the gauge can resolve the process variation.
- Bias, linearity and stability studies, and attribute agreement analysis for go/no-go decisions.
What an Auditor Asks to See
- The MSA plan for the control plan gauges, and the studies behind it.
- A study that failed, and what was done about it.
- How a new or repaired gauge is re-studied before use.
Where Systems Fall Short
- Studies run with parts that do not span the process range, which flatters the result.
- Attribute inspections never studied at all.
How QES Helps
MSA programs designed around the control plan, with studies run and interpreted alongside your own people.
Related Standards
Sources. AIAG — Automotive Industry Action Group publications (opens in a new tab). Status checked October 24, 2026. This page summarizes AIAG MSA; it does not reproduce or replace it. Buy the standard from its publisher, or read the regulation in its official text, before relying on a detail. Not legal advice.