An understanding of power is central to understanding of how organizations work.
without power there can be no discipline; without discipline there can be difficulty in maintaining order, system and productivity. An executive without power is, therefore, all too often a figurehead or worse, headless. The higher an executive is in the management hierarchy, the greater his need for power. This is because power tends to weaken as it disseminates downwards.
Robert N. McMurry, "Power and the Ambitious Executive" in Harvard Business Review (NovemberDecember 1973)
However, power is a problematic and messy concept. Almost every author who writes about power defines id differently. For example, Max Weber defined power as
...the probability that one actor within a social relationship will be in a position to carry out his own will despite resistance.
Political scientist Robert Dahl has defined power in the following way:
A has power over B to the extent that he can get B to do something B would not otherwise do.
Robert Dahl, "The Concept of Power" Behavioral Science (July 1957)
Other definitions stress goals or organizational outcomes. Another term, influence, is also frequently used when discussing the notion of power. However, influence tends to be subtler, broader, and more general than power. It is weaker and less reliable than power.
The terms, power and authority , while closely related, do not mean exactly the same thing.
Authority is the right to command subordinates and expect compliance. This right results from having a legitimized position of power in the organization. Power is much broader in meaning and implication: it need not to bee legitimate.
Chester Barnard distinguished bureaucratic authority and authority based upon acceptance and defined authority as "the character of a communication (order) in a formal organization by virtue of which it is accepted by a contributor to or "member" of the organization as governing the action he contributes".