Today you may belong to multiple teams working on differing plans. The matrixed environment of todays firms means that you may be reporting to more than one person. This does not necessarily negate Fayol’s principle. I see wisdom in the bottom line leadership of an effort being invested into one person who leads a team. If there is a separation of duties to other teams or sets of workers, then the reporting should still go back to the main person overseeing the plan.