MSA Continuous Data – Gauge R&R

[#1]

This guide provides instructions on creating a variability chart and performing a gauge R&R (Repeatability and Reproducibility) measurement system analysis (MSA). This analysis is designed to evaluate and certify the performance of a measurement system that produces continuous data. For information on using the EMP (Evaluating the Measurement Process) method, see the MSA Continuous Data – EMP Method guide.   

Measurement Systems Analysis: Variability Chart

1. Select Analyze > Quality and Process > Variability/Attribute Gauge Chart.
2. Select Variability under Chart Type.
3. Click on a continuous variable from Select Columns, and click Y, Response (continuous variables have blue triangles).
4. Select one or more grouping variables and click X, Grouping.
5. Select a part or sample variable and click Part, Sample ID.

 By default, JMP displays two plots:

• The Variability Chart for Y shows the individual measurements and range bars for each combination of the part and the grouping variables.  To better visualize sources of variation, select Connect Cell Means, Show Group Means and Show Grand Mean from the red triangle. 
• The standard deviations plot shows the standard deviation for each combination of the part and the grouping variables.

Performing a Gauge R&R: 

1. Select Gauge Studies > Gauge R&R from the red triangle.
2. In the Variability Model pop-up window, select the model type and click OK (the default is Crossed).
3. If specs are available, choose the tolerance entry method, enter either the Tolerance Range or the Spec Limits, and click OK. For this example: Tolerance Range (USL-LSL) = 100.

The resulting Gauge R&R and Variance Components for Gauge R&R reports quantify sources of measurement system variation.

Interpretation:
1. The % Gauge R&R is 23.86%. This is the percentage of the total variation being attributed to the measurement system.
2. The Precision/Tolerance Ratio (or the P/T Ratio) is 0.3396. 3. Variance Components for Gauge R&R: The measurement system (Gauge R&R) accounts for 5.69% of the total variation in the study.

Notes:  To conduct Bias and Linearity studies, specify a standard (or reference column) in the dialog window. Additional options are available from the top red triangle.

Gasket.jmp (Help > Sample Data Folder > Variability Data)

Visit Quality and Process Methods > Variability Gauge Charts in JMP Help to learn more.