Results - Brushing Tab

Select the Brushing tab of the Results dialog box to access options to highlight specific samples in your data set.  

Include/exclude samples

The options in the Include/exclude samples group box are used to toggle between individual samples in the graph.

Selected

To highlight a specific point (sample), mark the Selected button.  You can pick the sample to brush using the Sample <<, >> buttons or by clicking on the MicroScroll buttons next to the list box. The box shows the sample labels (numbers) and can be sorted by sample labels (numbers), magnitude of X-bar chart values, or magnitude of R/S chart values by selecting the appropriate option in the drop-down box below it. Whenever you click on a different sample in the list field, the information shown in the Summary box will be updated. You can select multiple samples by pressing the CTRL key on your keyboard and selecting the samples from the list.

All out-of-control samples

Select this option button to automatically highlight all out-of-control samples in the chart. When this option is chosen, the types of out-of-control points will be listed below the option (e.g., out of limits, runs violations) giving the user an idea of what types of violations have occurred in the data set.  

Always select last sample

Select this option button to automatically highlight the last sample in the data set. This option is particularly useful in conjunction with the Show Stats check box, when you are continuously updating the chart. If you select the Always select last sample option button, the Show Stats window will always show the statistics for the most recent sample in the chart.

Including/Excluding points from calculations/graphs

Once you have highlighted the samples of interest, you can further analyze them by excluding them from the calculation of the control limits and process parameters (via the Exclude from computations check box) or excluding them from the graph altogether (via the Exclude (drop) from graph check box). For example, if you find assignable causes for out-of-control points, you could exclude those points from the computation of process parameters. However, you may still want to display the out-of-control samples in the QC charts. Note that whenever individual samples should be excluded/included from the computations of the control limits, an additional variable must be specified in the data set. This variable will contain sample inclusion codes. This variable can be added during the analysis (via the Setup button, see below).

Assigning Causes and Actions to highlighted samples

Once out-of-control points have been identified (highlighted), you can add labels for causes, actions or comments to those points. These labels can be used to illustrate why certain points have been excluded from computations of the process parameters.

The data set needs to include separate variables for causes, actions, and additional comments (optional). These variables could be set up prior to the analysis, or they can be created by using the Setup button in the results dialog box. See the Causes, Actions, Comments and Data Brushing Setup dialog box topic for more details on how to create these variables.

Cause

Click the Cause button to label the highlighted point with an explanation of what caused the out-of-control point. When you click this button, a variable selection dialog box will be displayed where you can select the variable that contains the predefined causes. Once this variable is selected, the Assigning a Cause dialog box will be displayed. Here you can either select from predefined causes or create a new cause.

Action

Click the Action button to label the highlighted point with a brief description of the action taken to correct the situation that led to the out-of-control point. When you click this button, a variable selection dialog box will be displayed where you can select the variable that contains the predefined actions. Once this variable is selected, the Assigning an Action dialog box will be displayed. Here you can either select from predefined actions or create a new action.

Comment

Click the Comment button to label the highlighted point with any additional comments you have about the out-of-control (or highlighted) point. When you click this button, a variable selection dialog box will be displayed where you can select the variable that contains the predefined comments. Once this variable is selected, the Assigning a Comment dialog box will be displayed. Here you can either select from predefined comments or create a new comment.

Setup

Click the Setup button to display the Causes, Actions, Comments and Data Brushing Setup dialog box, which is used to create the variables and codes/text values for causes, actions and comments.

Report

Click the Report button to send information about the variable to a report.

Additional Options

Show stats

Select the Show stats check box to show various statistics for the highlighted points. The sample stats (which have been requested in the Stats tab of the Options dialog box) will be displayed when you click on the respective individual samples in the list box. The Sample Stats box will display all the requested statistics. This box will update as you select different samples from the drop-down list field.

Show or Hide individual observations

In order to further analyze the out-of-control (or highlighted) samples, you can have the individual observations for those samples displayed in the QC graph. To show the observations, select the Show check box. When the chart is updated, the X-bar chart portion of the QC graph will display the individual observations for the highlighted points. This option is not available if the input data file contains aggregated data (sample means and ranges or standard deviations; in that case plots of individual measurements or observations as well as process capability histograms of observations cannot be created).

Note: instead of using this tab to examine individual samples, you can examine points graphically (brushing mode) using the Brush button in the lower part of the Results dialog box.