Complex sentence: The Peter principle is a concept in management theory formulated by Laurence J. Peter and published in 1969 in which the selection of a candidate for a position is based on the candidate's performance in their current role, rather than on abilities relevant to the intended role.
Split into simpler sentences: The Peter principle is a concept in management theory formulated by Laurence J. Peter and published in 1969. The theory is that the selection of a candidate for a position is based on the candidate's performance in their current role, rather than on abilities relevant to the intended role.