1.
Select Help > Sample Data Library and open Consumer Prices.jmp.
2.
Select Analyze > Screening > Process Screening.
3.
Select Price and click Process Variables.
4.
Select Series and click Grouping.
This ensures that each level of Series is treated as a separate process.
5.
Select Date and click Time.
6.
Set the Control Chart Type to XBar and R.
7.
Set the Subgroup Sample Size to 3.
8.
10.
Check the following: Largest Upshift, Largest Downshift, and Shift Graph.
11.
A Shift Graph also appears. The Shift Graph shows all shifts that exceed the number of Shift Threshold within-sigma units, which is set to three by default. See Shift Graph. Green points correspond to upshifts and red points correspond to downshifts.
Notice that Gasoline, All has values for both Largest Upshift and Largest Downshift in the Summary table. The Largest Downshift value, 1.8296, is less than three. Because the Shift Graph shows shifts of only three or more within-sigma units, the Largest Downshift value for Gasoline, All is not plotted on the Shift Graph.
Also notice that Tomatoes is not included on the Shift Graph. For Tomatoes, no shifts of three or more within-sigma units were found.
13.
14.
Set Label Row Nesting to 2.
15.
Figure 18.7 Shift Graph
Figure 18.8 Control Chart for Coffee
The Summary table indicates that the largest upshift (25.399 within-sigma units) occurs for the subgroup that includes September 1994. In the control chart in Figure 18.8, this is the subgroup in position 59. The Summary table also indicates that the largest downshift (9.1674 within-sigma units) occurs for the subgroup that includes March 1981. This is the subgroup in position 5 in the control chart.

Help created on 10/11/2018