Walter A. Shewhart Quotes

Postulate 1. All chance systems of causes are not alike in the sense that they enable us to predict the future in terms of the past.

Postulate 3. Assignable causes of variation may be found and eliminated.

Rule 1. Original data should be presented in a way that will preserve the evidence in the original data for all the predictions assumed to be useful.

Postulate 2. Constant systems of chance causes do exist in nature.