Example of the Data Units Option in a CUSUM Control Chart
This example uses the Data Units option to detect small shifts in the temperature of an engine. The data table contains temperature measurements from the engine thermostat.
Note: This example reproduces the analysis in Example of a CUSUM Control Chart using the data units option.
1. Select Help > Sample Data Folder and open Quality Control/Engine Temperature Sensor.jmp.
2. Select Analyze > Quality and Process > Control Chart > CUSUM Control Chart.
3. Select Y and click Y.
4. Select the box next to Data Units.
5. Click OK.
6. In the Target box, type 100.
7. In the Sigma box, type 10.
Note that the options below Head Start are H and K, instead of h and k. These parameters are now specified in units of the data column, rather than in standard deviation units.
Figure 10.6 CUSUM Control Chart Report
Like in the example using sigma units, the vertical line on the CUSUM Chart indicates that a shift in the temperature measurements started around sample 26.