- https://en.wikipedia.org/wiki/Six_Sigma
- https://www.lean.org/explore-lean/the-lean-transformation-framework/
- https://kaizen.com/what-is-kaizen/
- https://www.iso.org/standard/62085.html
- https://fourweekmba.com/total-quality-management/
- https://www.thoughtworks.com/insights/blog/agile-quality-management-model
- https://efqm.org/the-efqm-model/