X and R Chart Phase Example
1.
Open the Diameter.jmp sample data table in the Quality Control folder.
2.
Select Analyze > Quality and Process > Control Chart Builder.
3.
Drag DIAMETER to the Y role.
4.
Drag DAY to the Subgroup role.
Control Charts for Diameter
5.
Drag Phase to the Phase role.
6.
In the Average chart, right-click and select Warnings > Test Beyond Limits.
Control Charts for each Phase
Including the Phase variable means that the control limits for phase 2 are based only on the data for phase 2. None of the phase 2 observations are outside the control limits. Therefore, you can conclude that the process is in control after the adjustments were made.
The Washers.jmp sample data contains defect data for two different lot sizes from the ASTM Manual on Presentation of Data and Control Chart Analysis, American Society for Testing and Materials. To view the differences between constant and variable sample sizes, you can compare charts for Lot Size and Lot Size 2.
1.
Open the Washers.jmp sample data table in the Quality Control folder.
2.
Select Analyze > Quality and Process > Control Chart Builder.
3.
Drag # defective to the Y role.
4.
Select Shewhart Attribute from the drop down to change the chart to an attribute chart.
5.
Change the Sigma to Binomial to change the chart to a np-chart.
6.
Change the Statistic from Count to Proportion to change the chart to a p-chart.
p-chart of # defective
7.
Drag Lot SIze to the nTrials role.
p-chart of # defective with sample size
To view the differences between constant and variable sample sizes, you can compare charts for Lot Size and Lot Size 2 by simply dragging the variables to the nTrials zone.
The Bottle Tops.jmp sample data contains simulated data from a bottle top manufacturing process. Sample is the sample ID number for each bottle. Conforming indicates whether the bottle top met the design standards. In the Phase column, the first phase represents the time before the process adjustment. The second phase represents the time after the process adjustment. Notes on changes in the process are also included.
1.
Open the Bottle Tops.jmp sample data table in the Quality Control folder.
2.
Select Analyze > Quality and Process > Control Chart Builder.
3.
Drag Conforming to the Y role.
4.
Drag Sample to the Subgroup role.
np-chart of Conforming
The original observations appear to have high variability and there are five observations (Samples 13, 15, 21, 22 and 23) that are outside of the upper control limit. Samples 15 and 23 note that new material and a new operator were introduced into the process, respectively. At the end of the phase, an adjustment was made to the manufacturing equipment. Therefore, the control limits for the entire series should not be used to assess the control during phase 2.
5.
Drag Phase to the Phase zone.
np-chart for each Phase
Including the Phase variable means that the control limits for phase 2 are based only on the data for phase 2. None of the phase 2 observations are outside the control limits. Therefore, you can conclude that the process is in control after the adjustment.
The Cabinet Defects.jmp sample data table contains data concerning the various defects discovered while manufacturing cabinets over two time periods.
1.
Open the Cabinet Defects.jmp sample data table in the Quality Control folder.
2.
Select Analyze > Quality and Process > Control Chart Builder.
3.
Drag Type of Defect to the Y role.
4.
Drag Lot Number to the Subgroup role.
A np-chart of Type of Defect appears.
5.
To change to a c-chart, select Poisson from the Sigma list.
6.
Open the Event Chooser disclosure button. Note all of the defect types are listed. Currently, only Bruised veneer is selected and displayed in the chart. You can select additional defect types and the chart updates immediately.
c-chart of Type of Defect
7.
To add to phase variable, drag Date to the Phase zone.
c-chart of Type of Defect with Phases
The Shirts.jmp sample data table contains data concerning the number of defects found in a number of boxes of shirts.
1.
Open the Shirts.jmp sample data table in the Quality Control folder.
2.
Select Analyze > Quality and Process > Control Chart Builder.
3.
Drag # Defects to the Y role.
4.
Drag Box to the Subgroup role.
5.
To change the chart to an Attribute chart, select Shewhart Attribute from the drop down list.
A c-chart of # Defects appears.
6.
Change the Statistic from Count to Proportion to change the chart to a u-chart.
u-chart of # Defects
1.
Open the Adverse Reactions.jmp sample data table in the Quality Control folder.
2.
Select Analyze > Quality and Process > Control Chart Builder.
3.
Drag Doses since Last ADE to the Y role.
4.
Drag Date of ADE to the Subgroup role.
5.
To change the chart to a Rare Event chart, select Rare Event from the drop down list.
g-chart of Doses since Last ADE
1.
Open the Fan Burnout.jmp sample data table in the Quality Control folder.
2.
Select Analyze > Quality and Process > Control Chart Builder.
3.
Drag Hours between Burnouts to the Y role.
4.
Drag Burnout to the Subgroup role.
5.
To change the chart to a Rare Event chart, select Rare Event from the drop down list.
6.
Change the Sigma from Negative Binomial to Weibull to change the chart to a t-chart.
t-chart of Hours Between Burnouts