2. Lesson 3
Stabilize the Process

3. Objectives You will be able to understand:
Key activities for process stability
Difference between special and common cause variation
Responsibilities for taking action on variation
Difference between specifications and control limits

4. Lesson 3: Stabilize the Process
Activity 3.1 Determine process measures
Activity 3.2 Examine the process by using
control charts
Activity 3.3 Act on special causes
Activity 3.4 Check for capability

5. Activity 3.1 Determine Process
Measures
Process measures must: - be objective and representative of the process - measure appropriate quality characteristics
Flow charts are useful tools for determining process measures

6. Determine Process Measures
Products
&
Services
CVN
Processes
Air
Wing
Suppliers
Inputs
Processes
Outputs
Outcomes
Quality of supplies
Time to deliver
Condition of materials
Accuracy of information
etc.
Ordnance assembly
Moving ordnance
Staging ordnance
etc.
Launch / recover
Berthing / messing
Training time
etc.
Timely launch / recovery
Safe launch / recovery
Effective launch / recovery
Satisfaction with service
etc.

7. Run Chart Line graph showing variation plotted over time55 50 45
Elapsed Time (minutes) 40
Average 35 30
Sequence
Line graph showing variation plotted over time

8. Activity 3.2 Examine the Process by using Control Charts
Upper
Control
Limit
Average
Measurement
Lower
Control
Limit
Time or Sequence
Line graph that shows process variation
Limits calculated from process data

9. Common Causes Data appear randomly
UCL
Average
Measurement
LCL
Time or sequence
Data appear randomly
Control limits provide predictable range

10. Special Causes Appear as nonrandom variation Are not predictable UCL
Average
Measurement
LCL
Time or sequence
Appear as nonrandom variation
Are not predictable

11. Activity 3.3 Act on Special
Causes
Common Causes:
- Inherent in the process
- Affect everyone in the process
- Affect all outcomes of the process
Special Causes:
- Are not in the process all the time
- Do not affect everyone in the process
- Arise because of specific circumstances

12. Responsibility for Reducing Variation
Special cause - people working in the process
Common cause - command’s leaders & managers

13. Avoid Tampering and Underadjusting
Taking action when no action is needed
Failing to act when action is required

14. Specifications vs Control Limits
UCL
Measurement
Specifications
LCL
Time or sequence

15. Activity 3.4 Check for Capability
Unstable - Measures fall outside control limits, or - Measures show non-random pattern
Stable - Measures fall randomly within control limits
Capable - Stable process that also meets customer or mission requirements

16. Stability and Capability
UCL
USL
LSL
LCL
Situation 1

17. Stability and Capability
USL
UCL
LCL
LSL
Situation 2

18. Stability and Capability
UCL
USL
LCL
LSL
Situation 3

19. Stability and Capability
USL
UCL
LCL
LSL
Situation 4

20. Lesson Summary Stabilize the Process
Activity 3.1 Determine process measures
Activity 3.2 Examine the process by using
control charts
Activity 3.3 Act on special causes
Activity 3.4 Check for capability