In a hierarchy every employee tends to rise to their level of incompetence.
It holds that in a hierarchy, members are promoted so long as they work competently. Sooner or later they are promoted to a position at which they are no longer competent (their “level of incompetence”), and there they remain, being unable to earn further promotions. This principle can be modelled and has theoretical validity. Peter’s Corollary states that “in time, every post tends to be occupied by an employee who is incompetent to carry out their duties” and adds that “work is accomplished by those employees who have not yet reached their level of incompetence”.