© 2004 Cayman Business Systems
Rev: Pre-G3 - Rendered  Thursday, February 12, 2004
Slide 48
Elsmar.com  --- The Cove!
8-Disciplines Problem Solving
Elsmar.com
•Structural Variation is regular, systematic changes in output. Typical examples include seasonal patterns and long-term trends.
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Structural Variation
Structural Variation is of special note here. Some folks break out variation into four categories:
   Special Cause
   Common Cause
   Tampering
   Structural Variation
You can consider both Structural and Tampering variation as Common Cause variation. For example, the semi-conductor industry, as well as many other industries, have ‘clean rooms’ or other climate and interference controlled (noise, vibration, temperature, humidity, air particle level, etc.) facilities. By not operating in air conditioning during the summer, management has built into the system a significant source of pollution / interference.