Measurements are used to guide decisions. And measurement error can lead to error in the decisions based on those measurements.  Thus it is critical that we understand the quality of the measurements we are using—how much error does the system create, and how do the measurement values we create relate to the real-life requirement?

The purpose of Measurement System Analysis (MSA) is to quantify the measurement error created due to accuracy, precision, and stability.   A proper MSA will confirm that the measurement equipment selected for use in the development or production process is suitable for the application.

In an MSA, in addition to quantifying error due to repeatability and reproducibility (Gage R&R), we leverage known standards (with “True Values” that are often traceable to a reference source) to assess accuracy and linearity.  However, in many cases we don’t have standards for the characteristic being measured.  In situations like this—even for a perfectly precise gage—it is impossible to know how accurate the gage is….and thus it can be impossible to know if the parts being measured on it are conforming or non-conforming units. 

The solution to this problem is a Measurement Systems Correlation (MSC).  An MSC is a designed experiment that allows us to establish the relationship between a “Gold” tester (which originates the specifications) and any other testers (typically production testers) that are responsible for measuring (and dispositioning) product.

Take the Next Step!
Learn more about MSA here.  Download a standard study template here or a short study template here.

Learn more about MSC here.  Download an MSC template here.

Got a question?  Ask the Expert!

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