The literal meaning of hierarchy is the rule of control of the higher over the lower. Hierarchy means a graded organisation of several successive levels in which one of the lower level is immediately subordinate to the next higher one and through it to the other higher steps right up to the top. The shape of the administrative structure is that of a pyramid Mooney and Reily call it the scalar process They say ―a scale means a series of steps something graded. In organisation it means the grading of duties not according to different functions, but according to degrees of authority and corresponding responsibility.
The basic features of the hierarchical structure are:
a. A person will have only one immediate superior from whom he will receive orders.
b. A person will not receive orders from lower status.
c. No intermediate level shall be skipped over in the dealing of the people at the top with those lower level or vice versa.
d. A person who is given responsibility for a task will have authority commensurate with this responsibility.
From the above features it is clear that in the scalar system authority command and control descend from the top to the bottom step by step. The secretary of department will deal with the joint secretary who in turn shall deal with the deputy secretary who further shall deal with the under secretary. The under secretary shall further deal with the section officer who in turn deal with assistants, clerks etc. Similarly, the upward communication shall also be exactly the same when a section officer deals with higher officers.
The two basic principles of unity of command and span of control are centrally indispensable to the study of organizational theory and practice in particular, and in general terms, to successful, efficient and smooth public administration practice in both developed and developing societies.
Span of Control
The principle of span of control means the number of subordinates or the units of work that an officer can personally direct, control, and supervise. It is also known as „span of supervision? or „span of management according to Dimock and Dimock, The span of control is the number and range of direct, habitual communication contacts between the chief executive of an enterprise and his principal fellow officers.span of control is meant that one of the earlier principles of administration which states that there is an upper limit to the number of subordinates any administrator can directly supervise, generally set at 12, and advises administrators to eliminate any violations of this principle by reducing the number of officials reporting to them by either emerging certain offices or stretching out the scalar chain
There is a close relationship between hierarchy and span of control. That is, the number of levels in a hierarchical (scalar) organisation depends upon the span of control of a superior officer. Narrow (smaller) span of control increases the number of levels in the organisation and thereby creates tall structure. On the other hand, wide (larger) span of control decreases their number and thereby results in a flat structure.
The principle of span of control in public administration is related to the concept of span of attention described in psychology by V Graicunus, the French management consultant. This concept says that there is a limit to the number of things one can attend to at the same time. In other words, the span of attention of a human being is limited as there are limits to the range of human capacity and attention. Thus, it follows that there is a limit to the span of control which is nothing but the span of attention applied to the job of supervision of subordinates by the superior.
Unity of command
Unity of command means that an employee should receive orders from one superior only. In other words, it means that no employee should be subjected to the order of more than one superior. Thus, it stands for single boss for each person or monocommand.
Unity of command means organizational principle that each person within the line of authority should be responsible to only other person. An employee who is responsible to various persons in authority will presumably be confused, ineffective and irresponsible, while an employee receiving commands from one supervisor is presumably methodical, efficient and responsible.