© 2004 Cayman Business
Systems
Rev:
Pre-G3 - Rendered Thursday,
February 12, 2004
Slide 42
Elsmar.com --- The
Cove!
8-Disciplines Problem Solving
•Distinguishing between the types of causes is critical because
the appropriate managerial actions are
quite different for each. Without this
distinction, management will never be able to tell real improvement from mere adjustment of the process or tampering.
•In practice, the most important difference to grasp first is the difference between special cause variation and common cause variation.
•The strategy for special
causes is simple: Get timely data. Investigate immediately when the data signals a special cause is/was
present. Find out what was different or special
about that point. Seek to prevent bad causes from recurring. Seek to keep good causes happening.
•The strategy for
improving a common cause system is more subtle. In a common cause situation, all the data are relevant, not
just the most recent or offending
figure. If you have data each month for the past two years, you will need to look at all of that data.
Process Variation