System of Profound Knowledge – SoPK

Deming advanced the System of Profound Knowledge (SoPK) which he said consisted of four main subheadings:

1. Knowledge of Variation, that is, a knowledge of common cause and special variation.

2. Knowledge of Systems, that is, understanding that all the parts of a business are related in such a way that if you focus on optimizing one part, other parts may suffer.
3. Knowledge of Psychology, that is, what motivates people.
4. Theory of Knowledge, that is, how we learn things.