RE: Methods to Determine Special vs. Common Cause

[Steven_S_Prevette@rl.gov]

I was wondering, are there any accepted methods to
separate common causes from special causes besides
control charts?  
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Although Dr. Deming (for valid reasons listed at the end) recommended
against the following methods, these methods can be used to separate common
cause from special cause:

ANOVA (Analysis of Variance)
Various tests of hypotheses (t-test, chi-square to name a few)
Regression analysis (with proper analysis of the residuals and/or prediction
intervals)

However, the first two methods disregard time series relations within the
data, and the third is very difficult to do properly.

Steve Prevette
QA Engineer, ESH Planning and Performance
Fluor Hanford, A Fluor Global Services Company
ASQ Certified Quality Engineer
steven_s_prevette@rl.gov
509-373-9371
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