Capability Indices—Key Exercises

IMPORTANT
It is extremely important that you set up and work within your own site to maintain your data integrity. If you work within any other site, you will compromise your own exercise data as well as the data of other students. Predictable exercise results require that your data be isolated in your own site.

Basic Data Setup

Viewing the Control Plan

Purpose: The purpose of this exercise is to view the control plan that is required for running this particular functionality.

Menu Path: Quality Management/Control Plan/Control Plan – Purchasing

  1. Open the Control Plan – Purchasing window.
  2. Query for part no. 29-OSP, Camshaft (Heat Treated).
  3. View the control plan and verify that its status is Active.

General Exercise for Control Plan—Purchasing

Required Data

Viewing the Created Analyses

Purpose: The purpose of this exercise is to show the required data that is used in the exercises below.

Menu Path: Quality Management/Control Plan/Control Plan – Purchasing

  1. Open the Control Plan – Purchasing window.
  2. Query for part no. 29-OSP, Camshaft (Heat Treated).
  3. Click the Purchase Order Analysis tab.
  4. Verify that at least two analyses, created on two different dates, are available and have Confirmed status.

General Exercise for Analysis and Results for Purchasing

Main Exercises

Calculating Capability Indices for a Purchased Part

Purpose: The purpose of this exercise is to show how to calculate capability indices for a purchased part.

Menu Path: Quality Management/Control Plan/Control Plan – Purchasing

  1. Open the Control Plan – Purchasing window and query for part no. 29-OSP, Camshaft (Heat Treated).
  2. On the Control Plan Line tab, select the Rockwell Hardness Test test operation line. Then right-click and click Capability Indices. The Capability Indices window appears.
  3. Under Capability Indices, define the date interval you want to use for the calculation by selecting the applicable dates in the From and To lists.
  4. If you have entered target values for Cp and Cpk in the control plan for the part, you can see them in this window under Target Values.
  5. Click Sample Data to view the test data that will be used for the calculation.
  6. Click Calculate to calculate Cp and Cpk. The results are shown in the lower part of the window. The results are also shown as ppm values.
  7. Close the window.

Creating a Capability Indices Graph

Purpose: The purpose of this exercise is to show you how to create a capability indices graph.

Menu Path: Quality Management/Control Plan/Control Plan – Purchasing

  1. Open the Control Plan – Purchasing window and query for part no. 29-OSP, Camshaft (Heat Treated).
  2. On the Control Plan Line tab, select the Rockwell Hardness Test test operation line. Then right-click and click Capability Graph. The Capability Indices – Graph window appear.
  3. Under Duration, define the date interval you want to use by selecting the applicable dates in the From and To lists.
  4. Under Frequency, click the applicable option (Monthly, Weekly, or Daily), preferably one day.
  5. Under Use Limits As, click the applicable option (Inner Limits, Outer Limits, or Both).
  6. Select the Cp and Cpk check boxes.
  7. Click Create Graph. You will receive a message indicating that a graph has been created. You also will be asked whether you want to view the chart. Click Yes. The graph appears. The values on the x-axis are according to the frequency you have chosen. In this case, you will have one point per day on the x-axis.

Calculating Capability Indices for a Manufactured Part

Purpose: The purpose of this exercise is to show how to calculate capability indices for a manufactured part.

Menu Path: Quality Management/Control Plan/Control Plan – Manufacturing

  1. Open the Control Plan – Manufacturing window and query for part no. 29-321, Camshaft.
  2. On the Control Plan Line tab, select the Measure Outside Diameter test operation line. Then right-click and click Capability Indices. The Capability Indices window appears.
  3. Under Capability Indices, define the date interval you want to use for the calculation by selecting the applicable dates in the From and To lists.
  4. If you have entered target values for Cp and Cpk in the control plan for the part, you can see them in this window under Target Values.
  5. Click Sample Data to view the test data that will be used for the calculation.
  6. Click Calculate to calculate Cp and Cpk. The results are shown in the lower part of the window. The results are also shown as ppm values.
  7. Close the window.

Creating a Capability Indices Graph

Purpose: The purpose of this exercise is to show how to create a capability indices graph.

Menu Path: Quality Management/Control Plan/Control Plan – Manufacturing

  1. Open the Control Plan – Manufacturing window and query for part no. 29-321, Camshaft.
  2. On the Control Plan Line tab, select the Measure Outside Diameter test operation line. Then right-click and click Capability Graph. The Capability Indices – Graph window appears.
  3. Under Duration, define the date interval you want to use by selecting the applicable dates in the From and To lists.
  4. Under Frequency, click the applicable option (Monthly, Weekly, or Daily), preferably one day.
  5. Under Use Limits As, click the applicable option (Inner Limits, Outer Limits, or Both).
  6. Select the Cp and Cpk check boxes.
  7. Click Create Graph. You will receive a message indicating that a graph has been created. You also will be asked whether you want to view the chart. Click Yes. The graph appears. The values on the x-axis are according to the frequency you have chosen. In this case, you will have one point per day on the x-axis.

Calculating Capability Indices for One or More Data Points

Purpose: The purpose of this exercise is to show how to calculate capability indices for one or more data points.

Menu Path: Quality Management/Capability Indices/Calculate – Capability Indices
Quality Management/Capability Indices/Overview – Calculated Capability Indices

  1. Open the Calculate – Capability Indices window.
  2. Click Calculate to open the Query window.
  3. In the Query window, select the conditions of the calculation (for example, part no. 29-320).
  4. Click OK.
  5. The Capability Indices – Calculate window appears. Choose a time period by selecting dates in the From Date and To Date lists.
  6. Enter a comment, if necessary.
  7. To have this calculation run as a background job, select the Send to Background Job check box. Note: If you have chosen to query for any calculated fields (such as Mean, Standard Deviation, Inner Cp, Inner Cpk, Outer Cpk, Inner Cp ppm, Inner Cpk ppm, Outer Cp ppm, or Outer Cpk ppm), it is recommended that you run the calculation as a background job because the calculation can be time-consuming.
  8. Click OK.
  9. View the calculated values in the following fields: Inner Cp, Inner Cpk, Outer Cp, Outer Cpk, Inner Cp ppm, Inner Cpk ppm, Outer Cp ppm, Outer Cpk ppm, Mean, and Standard Deviation.
  10. You can query and/or sort again to narrow down your data.
  11. If you want to view the measurement data used for the calculations, select the specific row in the Calculate – Capability Indices window, right-click, and then click Sample Data. This opens the Sample Data – Capability Indices window. The measurement data used for the calculations is displayed in the Result fields.
  12. Once you have generated a calculation, you can query for and/or sort by that calculation number. To view this information later, open the Overview – Calculated Capability Indices window and populate it.
  13. Select a line in Overview – Calculated Capability Indices window, right-click, and then click Calculation Details to open the Calculate – Capability Indices window.