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# What is an acceptable Gage R&R?

## What is an acceptable Gage R&R?

If the Total Gage R&R contribution in the %Study Var column (% Tolerance, %Process) is: Less than 10% – the measurement system is acceptable. Between 10% and 30% – the measurement system is acceptable depending on the application, the cost of the measuring device, cost of repair, or other factors.

### What is considered as acceptable NDC?

See page 47 of the AIAG MSA 4th edition for when ndc less than 5 is acceptable. Although not indicated in the AIAG book, you should have an ndc of at least 10 for a gage used for SPC. Anything less generates “chunky” data, and is virtually useless.

How do I learn Gage R&R?

For example, five parts are to be measured by three operators using three randomly selected gages, and each operator will measure each part twice. Thus, the total sample will be 5 × 3 × 3 × 2 = 90. In a standard GR&R study, more parts can be selected, but this is an unacceptably large sample size for expanded GR&R.

What is a primary benefit of Gage R & R?

The Gage R&R helps you distinguish how much of the variation is due to the scale mechanism. If the proportion of scale mechanism variation is a large part of the overall variation, then you won’t really know your true weight — or whether your new diet is working.

## What is NDC value?

The AIAG MSA manual defines the ndc as the number of categories of measured values that can be reliably dis- tinguished. To put it simply, you may count how many times the gauge repeatability and reproducibility GRR fits into the actual process variation. You always truncate the ndc, unless it is less than 1.

### How NDC is calculated?

The formula for calculation is NDC = 1.41*(PV/GR&R) Gauge Repeatability refers to the ability of a single operator (often a person) to get the same result repeatedly; Gauge Reproducibility refers to the measurements of multiple operators falling within a tight range.

What are the acceptance criteria for a GRR?

GRR acceptance criteria 1 No of distinct categories should be >= 4 2 Gage R&R as a %age of tolerance less than 10% – accept between 10 – 30% – can take it with caution, again depends… 3 Gage R&R as a %age of contribution should be less than part to part contribution. More

What are the acceptance criteria for Gage your and R?

General Acceptance Criteria of Gage R and R (Variable type MSA): Generally, the measurement device to be acceptable when GR&R will be < 10% or ndc (Number of distinct categories) ≥ 5.

## What are the accepted acceptance criteria for AIAG?

You look at the acceptance criteria from AIAG: If the % Gage R&R is under 10%, the measurement system is generally considered to be an adequate measurement system. If the % Gage R&R is between 10 % to 30%, the measurement system may be acceptable for some applications.

### When to use 10% or 30% as acceptance criteria?

It says on page 78 of AIAG’s Measurement Systems Analysis, 4th Edition that “every effort should be made to improve the measurement system” when it is unacceptable. There does not appear to be any rationale in using the values of 10% and 30% as the criteria. These have not changed over the years.