Viewing Descriptive Statistics
You can compute basic statistics for quality results associated with any collection plan element using the Descriptive Statistics window. You can enter selection criteria to find only specific quality results for the collection plan element.
You can create descriptive statistic views from "scratch" or you can create them by copying settings from another chart, descriptive statistic view, or custom report. Copying settings allows you to view the same subset of data in different ways. See: Copy Settings.
You can save your descriptive statistic view settings. You can recreate descriptive statistic view using these saved settings, and you can change these settings to create new views.
The statistics calculated include the sum, mean, variance, standard deviation, total number of occurrences (the count), number of null occurrences (that is, occurrences where a value was not entered for the collection element), maximum, minimum, and range.
If you select specification limits, you can also calculate Cp and Cpk values as you view descriptive statistics. Cp and Cpk are measures of process capability, which is defined as the measured, inherent reproducibly of the product turned out by the process. See: Cp and Cpk.
After viewing descriptive statistics, you can optionally export the raw data that was used to create the view. Exported data can be further analyzed using a spreadsheet or statistical analysis software package.
To create a descriptive statistic view using copy settings:
3. Enter missing information or change the copied information as required (See below).
You can change all copied settings except the collection plan.
To create a descriptive statistic view:
1. Navigate to the Descriptive Statistics window.
To save your settings, you must enter a statistic name.
3. Select the Collection Plan.
If you are updating a descriptive statistics view, you cannot change the collection plan.
5. Optionally, select the Specification Limits for the Cp and Cpk calculation using one of the following methods. If you do not select specification limits, Cp and Cpk are not calculated when statistical results are calculated and displayed.
Select Specification Element Specification Limits: To select specification element specification limits, select a Specification Name from the Specifications list of values and choose OK. When the Specification Limits window appears, the specification element specification limits (if any) are displayed. See: Defining Specification Elements.
Attention: The Specification list of values that appears displays only those Specifications that have the selected Statistical Element as a specification element.
Find Specification Element Specification Limits by Finding a Specification: If you do not know which specification has the required specification element specification limits, you can choose the Find Spec Limits button from the Specification Limits window. The Find Specifications window appears.
In the Find Specifications window, you can narrow your search criteria by choosing the specification type (Item Spec, Supplier Spec, or Customer Spec) and an Item or Item Category and Revision. If you select a Supplier Spec or Customer Spec specification type, you must also select the Customer or Supplier.
If you try to find an "item" specification, but a specification for that item cannot be found, Oracle Quality searches for a specification based on the category of the item entered. To determine the item category, the default category set you defined using the QA:Quality Category Set profile option is used. See: QA:Quality Category Set.
To select which quality results to include in the calculation:
1. In the Show Results Where region, select the Collection Element to use for your query.
3. If the condition selected requires a range, enter both the From and To value. If the condition requires a single value, enter only the From value. If the condition (not equals) requires a null character, do not enter anything. To create an In or Not in List, see Creating In and Not In Lists.
4. Repeat steps 1 through 3 until all selection conditions are entered.
To calculate and display statistical results:
To save your descriptive statistic settings:
- Choose the Save Settings button to save the inquiry settings.
To export chart results:
- If you are using the Oracle Quality statistics engine, choose Export Results from the Special Menu. If you are using the Statit Statistics Engine, choose Export to Statit from the Special Menu. See: Exporting Quality Results.
