Stated as "in a hierarchy every employee tends to rise to his level of incompetence", this principle states that people are promoted in organizations on the basis of their performance in t he current job till a level where they no longer demonstrate the abilities to perform the job to which they are promoted.
Diagrams
Originated from/Coined by
Laurence J. Peter
Further Reading/ References
https://www.forbes.com/sites/roddwagner/2018/04/10/new-evidence-the-peter-principle-is-real-and-what-to-do-about-it/#7eb378f41809
https://en.wikipedia.org/wiki/Peter_principle