Employees 'specialise' within particular functional areas, for example finance, design, production planning or sales. This allows organisations to select employees according to their aptitude for the specialist tasks they are required to perform. Division of labour into specialised tasks also leads to the grouping of related tasks into functional departments. Thus flows of work move horizontally through the structure, from department to department, across authority boundaries. These tasks are delegated, that is, communicated downward by management.
Employees are accountable, communicating the outcome of their tasks upward.
It follows that there is an inherent 'horizontal' isolation between employees at all hierarchical levels. This is an organisational barrier, caused by the absence of structural horizontal communication channels, rather than the absence of physical means to communicate. The hierarchical nature of classical organisations defines relationships between individuals in the different vertical 'strata'. The nature of these relationships is one of superiority and subordination. The existence of these relationships demands the establishment of vertical communication channels, as the scalar command structure implicit in the relationships themselves could not exist without such channels.