Quality Control Charts and Statistical Process Control
Task 4: Customizing for Control Charts
Numerous control charts are available in basic Customizing in the SAP standard release.
1. Check which reference axis has been set in QM Customizing for the control chart used above and the characteristic category, for which the control chart is set.
Simulate another control chart.
Solution 10: Inspection during Production with Statistical Process Control (SPC) in Production Order
Task 1: Use Control Chart in Inspection Results Recording
After planning the quality control card with the inspection characteristic in the routing, you want to represent the control chart in the results recording, and use this to valuate the inspection characteristic.
1. Create a new inspection point for the length inspection and record the inspection results. To do this, use an inspection from the previous exercise in the PLM420 training course.
Call the control chart for this inspection characteristic Shaft Length in the results recording.
Calculate the action limits and activate the control chart.
Make a note of the calculated action limits for the mean value track (4 decimal places).
____________________________________________________________
____________________________________________________________
Save the inspection results, and the changes you made to the control chart.
Hint: The acceptance charts are based on the predefined tolerances and determine the share of scrap in the process. Using these charts, if a long-term reduction in the process variance is achieved, the limits are extended.
Hint: With a Shewhart chart, in this case the limits become tighter.
These charts only take internal process parameters into account and not external tolerance specifications. In a continuously recurring statistical test, the hypothesis is tested that the established, controlled status of the process has not changed.
a) Results Recording Worklist
Material T-BQ6##
Plant 1000
Inspection lot origin 03 (entry is optional) Execute the function key F8.
Manually create inspection points, and enter the inspection results for the inspection characteristics, and complete the characteristics processing.
Hint: The characteristic Shaft Length is required for the additional exercises.
Create a new inspection point for the length inspection and record the inspection results.
Call up the control chart for this inspection characteristic. Use the corresponding pushbutton in the application function bar of the inspection results recording or the corresponding icon in the characteristic overview screen in the line for characteristic 20 in the inspection results recording.
Calculate the action limits and activate the control chart. Use the relevant icon in the inspection results recording graph.
Icon Enter control limits:
Here, you can see the calculated values for the upper and lower tolerance, the upper and lower warning limit, as well as the center line.
Save the inspection results. The changes in the control chart are automatically saved.
Task 2: SPC inspection
If the valuation mode 800 SPC inspection is used in the sampling procedure, the inspection characteristic is valuated according to the action limits of the quality control chart after activation.
1. Create additional inspection points for the length inspection of the shafts and record the inspection results.
Note the individual values when these are recorded. The sample is valuated based on the action limits in the control chart.
Save the inspection results.
Continued on next page
Check the changes to the control chart using the control chart worklist.
Which menu path did you use?
a) Results Recording Worklist
Logistics → Quality Management → Quality Inspection → Worklist → Results Recording (QE51N)
Field name or data type Values
Material T-BQ6##
Plant 1000
Inspection lot origin 03 (entry is optional) Execute the function key F8.
Hint: The characteristic Shaft Length is required for the additional exercises.
Create a new inspection point for the length inspection and record the inspection results.
Note the individual values when these are recorded. The sample is valuated based on the action limits in the control chart.
b) Display Quality Control Chart:
Logistics → Quality Management → Quality Inspection → Worklist → Quality Control Chart → For Inspection Lot (QGC1)
Field name or data type Values
Material T-BQ6##
Plant 1000
Inspection lot origin 03 Execute the function key F8.
Note the settings for the control chart status in the selection screen.
Task 3: Planning control charts
____________________________________________________________
Why is an x-bar/s-chart not advisable for a sample size of n=1?
____________________________________________________________
____________________________________________________________
____________________________________________________________
a) Automatic maintenance process if action limits are exceeded:
To create a quality notification, the indicator Auto. defects recording must be set in the control indicators for the inspection characteristic.
In addition, a 'Defect code for rejection' (general, at the upper or lower tolerance) must be maintained in the catalog for the inspection characteristic.
The defect class for the code must have the relevant Customizing setting to automatically activate the created quality notification.
The valuation of the characteristic in results recording must take place based on the action limits (valuation mode in the sampling procedure:
800 SPC inspection).
The standard deviation (s-chart) for a sample size of n=1 is always zero.
Task 4: Customizing for Control Charts
Numerous control charts are available in basic Customizing in the SAP standard release.
1. Check which reference axis has been set in QM Customizing for the control chart used above and the characteristic category, for which the control chart is set.
Simulate another control chart.
a) Transaction QCCO, then
Quality Management → Quality Planning → Basic Data → Sample, SPC → Statistical Process Control → Define Control Chart Type Display details for the control chart type
The control chart types 211 and 411 were used in the exercises.
Exercise 11: Inspection during Production with Statistical Process Control (SPC) in Process Order
Exercise Objectives
After completing this exercise, you will be able to:
• Plan an SPC characteristic
• Call and edit a control chart
Business Example
You produce tablets using process orders. To monitor the process, the
characteristic pH Value should be checked in 10 minute intervals. The mean value and standard deviation for the samples should be displayed in a control chart.
Task 1: Use Control Chart in Inspection Results Recording
After planning the quality control card with the inspection characteristic in the master recipe, you want to represent the control chart in the results recording, and use this to valuate the inspection characteristic.
1. Create a new inspection point for the pH value inspection of tablets and record inspection results. Use the inspection lot from the exercise on the subject inspection point processing - process order in the PLM420 training course.
Call the control chart (Shewhart chart) for this inspection characteristic (9-120) in the results recording.
Calculate the action limits and activate the control chart.
Make a note of the calculated action limits for the mean value track (4 decimal places).
____________________________________________________________
____________________________________________________________
Continued on next page
Save the inspection results, and the changes you made to the control chart.
Hint: The acceptance charts are based on the predefined tolerances and determine the share of scrap in the process. Using these charts, if a long-term reduction in the process variance is achieved, the limits are extended.
Hint: With a Shewhart chart, in this case the limits become tighter.
These charts only take internal process parameters into account and not external tolerance specifications. In a continuously recurring statistical test, the hypothesis is tested that the established, controlled status of the process has not changed.
Task 2: SPC inspection
If the valuation mode 800 SPC inspection is used in the sampling procedure, the inspection characteristic is valuated according to the action limits of the quality control chart after activation.
1. Create further inspection points for the pH value inspection of tablets and record inspection results.
Note the individual values when these are recorded. The sample is valuated based on the action limits in the control chart.
Save the inspection results.
Check the changes to the control chart using the control chart worklist.
Which menu path did you use?
Task 3: Planning control charts
Control charts can be planned for one inspection characteristic in the plan, and to valuate the inspection characteristic.
1. How do you plan the automatic triggering of an editing process, when the action limits in a control chart have been exceeded?
____________________________________________________________
____________________________________________________________
____________________________________________________________
Why is an x-bar/s-chart not advisable for a sample size of n=1?
____________________________________________________________
____________________________________________________________
____________________________________________________________
Task 4: Customizing for Control Charts
Numerous control charts are available in basic Customizing in the SAP standard release.
1. Check which reference axis has been set in QM Customizing for the control chart used above and the characteristic category, for which the control chart is set.
Simulate another control chart.
Solution 11: Inspection during Production with Statistical Process Control (SPC) in Process Order
Task 1: Use Control Chart in Inspection Results Recording
After planning the quality control card with the inspection characteristic in the master recipe, you want to represent the control chart in the results recording, and use this to valuate the inspection characteristic.
1. Create a new inspection point for the pH value inspection of tablets and record inspection results. Use the inspection lot from the exercise on the subject inspection point processing - process order in the PLM420 training course.
Call the control chart (Shewhart chart) for this inspection characteristic (9-120) in the results recording.
Calculate the action limits and activate the control chart.
Make a note of the calculated action limits for the mean value track (4 decimal places).
____________________________________________________________
____________________________________________________________
Save the inspection results, and the changes you made to the control chart.
Hint: The acceptance charts are based on the predefined tolerances and determine the share of scrap in the process. Using these charts, if a long-term reduction in the process variance is achieved, the limits are extended.
Hint: With a Shewhart chart, in this case the limits become tighter.
These charts only take internal process parameters into account and not external tolerance specifications. In a continuously recurring statistical test, the hypothesis is tested that the established, controlled status of the process has not changed.
a) Results Recording Worklist
Field name or data type Values
Material TAB-1##
Plant 1100
Inspection lot origin 03 (entry is optional) Execute the function key F8.
Manually create inspection points, and enter the inspection results for the inspection characteristics, and complete the characteristics processing.
Hint: The characteristic pH Value is required for the additional exercises.
Create a new inspection point for the pH value inspection of the tablet and record inspection results.
Call up the control chart for this inspection characteristic. Use the corresponding pushbutton in the application function bar of the inspection results recording or the corresponding icon in the characteristic overview screen in the line for characteristic 40 in the inspection results recording.
Calculate the action limits and activate the control chart. Use the relevant icon in the inspection results recording graph.
Icon Enter control limits:
Here, you can see the calculated values for the upper and lower tolerance, the upper and lower warning limit, as well as the center line.
Save the inspection results. The changes in the control chart are automatically saved.
Task 2: SPC inspection
If the valuation mode 800 SPC inspection is used in the sampling procedure, the inspection characteristic is valuated according to the action limits of the quality control chart after activation.
1. Create further inspection points for the pH value inspection of tablets and record inspection results.
Note the individual values when these are recorded. The sample is valuated based on the action limits in the control chart.
Save the inspection results.
Continued on next page
Check the changes to the control chart using the control chart worklist.
Which menu path did you use?
a) Results Recording Worklist
Logistics → Quality Management → Quality Inspection → Worklist → Results Recording (QE51N)
Field name or data type Values
Material TAB-1##
Plant 1100
Inspection lot origin 03 (entry is optional) Execute the function key F8.
Hint: The characteristic pH Value is required for the additional exercises.
Create a new inspection point for the pH value inspection of the tablet and record inspection results.
Note the individual values when these are recorded. The sample is valuated based on the action limits in the control chart.
b) Display Quality Control Chart:
Logistics → Quality Management → Quality Inspection → Worklist → Quality Control Chart → For Inspection Lot (QGC1)
Field name or data type Values
Material TAB-1##
Plant 1100
Inspection lot origin 03 Execute the function key F8.
Note the settings for the control chart status in the selection screen.
Task 3: Planning control charts
____________________________________________________________
Why is an x-bar/s-chart not advisable for a sample size of n=1?
____________________________________________________________
____________________________________________________________
____________________________________________________________
a) Automatic maintenance process if action limits are exceeded:
To create a quality notification, the indicator Auto. defects recording must be set in the control indicators for the inspection characteristic.
In addition, a 'Defect code for rejection' (general, at the upper or lower tolerance) must be maintained in the catalog for the inspection characteristic.
The defect class for the code must have the relevant Customizing setting to automatically activate the created quality notification.
The valuation of the characteristic in results recording must take place based on the action limits (valuation mode in the sampling procedure:
800 SPC inspection).
The standard deviation (s-chart) for a sample size of n=1 is always zero.
Task 4: Customizing for Control Charts
Numerous control charts are available in basic Customizing in the SAP standard release.
1. Check which reference axis has been set in QM Customizing for the control chart used above and the characteristic category, for which the control chart is set.
Simulate another control chart.
a) Transaction QCCO, then
Quality Management → Quality Planning → Basic Data → Sample, SPC → Statistical Process Control → Define Control Chart Type Display details for the control chart type.
The control chart type 116 was used in the exercise.
Lesson Summary
You should now be able to:
• Explain the control chart types in the SAP system and make Customizing settings
• Implement an inspection planning for an SPC inspection
• Use the functions of the control charts in the inspection results recording