The TOC study of bottlenecks in the process flow happens by identifying constraints and focusing on how to alleviate them by restructuring around them.

The system of profound knowledge is the study by W$.$ Edwards Deming of uniformity and how it benefits processes within organization.

Lean economic model was first implemented by Toyota to improve its production systems by adding three major constraints to effective production.

The system of Profound Knowledge uses four specific ways which includes understand variation and understand the theory of knowledge.