ADDITIVE Interface Package for Measurement System Analyses according to VDA 5 for Minitab

In German-speaking countries, measurement system analyses use methods based on the book „Mess- und Prüfprozesse“ („Measuring and Testing Processes”, VDA 5) published by the German Association of the Automotive Industry. However, Minitab does not offer its own solution for this. Many of the measurement system analyses in the statistical software are based on the work „Measurement Systems Analysis Reference Manual, 4th edition“ (MSA4) of the Automotive Industry Action Group (AIAG).

To cover the German-speaking market, we from ADDITIVE have developed an interface package that can be implemented in Minitab and, thus, enables the measurement system analysis according to VDA 5 in the software as well.

VDA 5 differentiates between three methods of measurement system analysis: Method 1 analyses the measuring system. Among other things, the bias, linearity and repeatability are examined on one or more reference parts using the measuring equipment. Method 2 follows chronologically after method 1 and analyses the measuring process. To this end, different parts are measured by different appraisers in order to evaluate repeatability and reproducibility or their respective precision. Like method 2, method 3 analyses the measuring process. However, it differs in that the operator’s influence is assumed to be negligible.

Method 1

Among other things, method 1 is used to examine the bias, linearity and repeatability on one or more reference parts using the measuring equipment. Depending on the task, Minitab offers tools like Type 1 Gage Study and Gage Linearity and Bias Study.

In a Type 1 Gage Study, for example, an appraiser measures a reference part or a standard several times and then estimates a standard deviation s_g and the capability indices Cg and Cgk. With a capable measuring system, these are equal to or greater than the reference value of 1.33.

These capability indices and the Type 1 Gage Study are not part of MSA4, however, the book contains a bias analysis. Type 1 Gage Study’s goal is to estimate the repeatability or the repeatability combined with the bias.

For method 1, the VDA 5 contains the standard uncertainties u_EVR (repeatability, identical to s_g), u_BI (from bias) and, also u_RE (resolution) as well as the calibration uncertainty u_CAL and the linearity deviation u_LIN. By using the standard uncertainties, a so-called suitability index Q_MS of the measurement system is calculated which must fall below a required suitability limit value Q_{MS_max}.

Method 2

In a measurement system analysis according to method 2, different parts are measured by different appraisers in order to evaluate repeatability and reproducibility. Minitab offers the tools Crossed Gage R&R Study as well as the Nested Gage R&R Study for destructive tests. When performing a Crossed Gage R&R Study, each part will be measured by each appraiser several times, whereas for a Nested Gage R&R Study, each appraiser measures several parts that are assumed to be identical from several batches of parts. With the measurement system analysis according to method 2 an attempt is made to separate the percentage of the differences between the parts (%parts) and the percentage of the variation in the measurement system (%R&R) with regard to the overall variation of the measurement data. The latter percentage should be as equal as possible. To detect the sources of the variation’s proportion %R&R, the proportional value of repeatability and reproducibility are output, too. The interaction of appraiser and part will be examined additionally by using the ANOVA of the Crossed Gage R&R Study. MSA4 includes guidelines to determine for which proportion %R&R the measurement system is acceptable, conditionally acceptable or not acceptable. Please see in Mintab’s online help: „Is the measurement system acceptable?”

The VDA 5 contains further standard uncertainties, including u_EVO (repeatability), u_AV (comparability of appraisers), u_GV (comparability of measuring points), u_STAB (stability or comparability of different points in time as well as one or more interactions u_IAi). A suitability index Q_MP of the measuring process is calculated from the standard uncertainties which, in an appropriate measuring process, does not fall below a required suitability limit value Q_{MP_max}.

Method 3

A measurement system analysis according to method 3 differs from an analysis according to method 2 in that the operator’s influence is assumed to be negligible. The value of the reproducibility or the default uncertainty u_AVis omitted here.

Are there other influences on the measuring process?
If you assume that there are other influencing factors on the measurement system apart from appraiser and part, Minitab provides the tool Expanded Gage R&R Study to analyse them.

How can ADDITIVE GmbH support me when implementing VDA 5 methods in Minitab?

You require a service package in addition to the Minitab licences to be able to use the ADDITIVE Interface Package. Please contact our Minitab sales team via e-mail to This email address is being protected from spambots. You need JavaScript enabled to view it.or by phone at +49 6032 34956 - 132.

Detailed description of the function on our support pages

You can find a detailed function description of the VDA 5 Interface Package on our ADDITIVE Minitools support pages.