SAS/QC Software

Gage Repeatability and Reproducibility

Measurement systems are essential to the quality of a manufacturing process. The measurement process itself is subject to variation, and excessive variation in the measurement instruments, referred to as gages, can mask critical variation in the manufacturing process.

One type of measurement variation is caused by conditions inherent in the gages. This variation, known as repeatability, occurs when one person measures the same characteristic several times with the same gage. Another type of measurement variation, known as reproducibility, occurs when different individuals measure the same characteristic with the same gage. Other sources of measurement variation include part-to-part variation and lack of accuracy, stability, and linearity.

GAGE Display Screen
GAGE Display Screen

The SAS System provides a point-and-click interface, referred to as the GAGE Application, for assessing gage R & R. This application provides range charts and average charts, which are commonly used in the semiconductor and automotive industries, and it also provides a more flexible variance components method. A variety of gage R & R methods are used in practice, and increasingly refined techniques of analysis are being introduced that make use of variance components and mixed model analysis. The GAGE application is designed so that it can easily be modified to suit local requirements.

GAGE R & R Application Features