Example of a Legacy Control Chart
This example uses the Coating.jmp sample data table in the Quality Control sample data folder (taken from the ASTM Manual on Presentation of Data and Control Chart Analysis). The quality characteristic of interest is the Weight column. A subgroup sample of four is chosen.
1. Select Help > Sample Data Library and open Quality Control/Coating.jmp.
2. Select Analyze > Quality And Process > Legacy Control Charts > XBar.
Note the selected chart types of XBar and R.
3. Select Weight and click Process.
4. Select Sample and click Sample Label.
5. Click OK.
Figure 12.2 Variables Charts for Coating Data
An XBar chart and an R chart for the process are shown in Figure 12.2. Sample six indicates that the process is not in statistical control. To check the sample values, click the sample six summary point on either control chart. The corresponding rows highlight in the data table.
Note: If an S chart is chosen with the XBar chart, then the limits for the XBar chart are based on the standard deviation. Otherwise, the limits for the XBar chart are based on the range.