Administration is a process of rational adaptation of means to ends. You can call it rational decision making, with the decision as the basic unit of analysis.

In a segmented flow of piecemal decisions, bureaucracy makes for a stabler and more efficient administrative environment. Bureaucracy is a particular form of administration, characterized by size, division of labor, formal rules, full-time staff, hierarchical relations. A process which tends to be combined with a more or less high degree of administrative centralism, according to the sector or "arena" of state activity and in response to the quest for autonomy and self-government by private groups.