2. Measurement Process Characterization
2.4. Gauge R & R studies

2.4.2.

Design considerations

Design considerations

Design considerations for a gauge study are choices of:

• Artifacts (check standards)
• Operators
• Gauges
• Parameter levels
• Configurations, etc.

Selection of artifacts or check standards

The artifacts for the study are check standards or test items of a type that are typically measured with the gauges under study. It may be necessary to include check standards for different parameter levels if the gauge is a multi-response instrument. The discussion of check standards should be reviewed to determine the suitability of available artifacts.

Number of artifacts

The number of artifacts for the study should be Q (Q > 2). Check standards for a gauge study are needed only for the limited time period (two or three months) of the study.

Selection of operators

Only those operators who are trained and experienced with the gauges should be enlisted in the study, with the following constraints:

• If there is a small number of operators who are familiar with the gauges, they should all be included in the study.
• If the study is intended to be representative of a large pool of operators, then a random sample of L (L > 2) operators should be chosen from the pool.
• If there is only one operator for the gauge type, that operator should make measurements on K (K > 2) days.

Selection of gauges

If there is only a small number of gauges in the facility, then all gauges should be included in the study.

If the study is intended to represent a larger pool of gauges, then a random sample of I (I > 3) gauges should be chosen for the study.

Limit the initial study

If the gauges operate at several parameter levels (for example; frequencies), an initial study should be carried out at 1 or 2 levels before a larger study is undertaken.

If there are differences in the way that the gauge can be operated, an initial study should be carried out for one or two configurations before a larger study is undertaken.