Scalar chain is the formal line of authority which moves from highest to lowest rank in a straight line. This chain specifies the route through which the information is to be communicated to the desired location/person.
Fayol emphasized that every information in the organization must flow according to this chain to facilitate clear communication of orders of the superiors and feelings of the subordinates. This chain must be strictly followed in the organization. Fayol also stated that there should be no overlapping of steps during the communication process.