Quality and Reliability Methods - SAS

30 Statistical Control Charts Chapter 2
The Control Chart Launch Dialog
Figure 2.4 Variables Charts with Unequal Subgroup Sample Sizes
Phase
The Phase role enables you to specify a column identifying different phases, or sections. A phase is a group
of consecutive observations in the data table. For example, phases might correspond to time periods during
which a new process is brought into production and then put through successive changes. Phases generate,
for each level of the specified Phase variable, a new sigma, set of limits, zones, and resulting tests. See
“Phases” on page 91 in the “Shewhart Control Charts” chapter for complete details of phases. For the
Diameter.jmp data, found in the Quality Control sample data folder, launch an XBar Control Chart. Then
specify Diameter as Process, Day as Sample Label, Phase as Phase, and check the box beside S for an S
control chart to obtain the two phases shown in Figure 2.5.