Pre-bureaucratic structures
Pre-bureaucratic (entrepreneurial) structures lack standardization of tasks. This structure is most common in smaller organizations and is best used to solve simple tasks. The structure is totally centralized. The strategic leader makes all key decisions and most communication is done by one on one conversations. It is particularly useful for new (entrepreneurial) business as it enables the founder to control growth and development.
They are usually based on traditional domination or charismatic domination in the sense of Max Weber's tripartite classification of authority.  Bureaucratic structures
Bureaucratic structures have a certain degree of standardization. They are better suited for more complex or larger scale organizations. They usually adopt a tall structure. Then tension between bureaucratic structures and non-bureaucratic is echoed in Burns and Stalker distinction between mechanistic and organic structures.  Post-bureaucratic
The term of post bureaucratic is used in two senses in the organizational literature: one generic and one much more specific . In the generic sense the term post bureaucratic is often used to describe a range of ideas developed since the 1980s that specifically contrast themselves with Weber's ideal type bureaucracy. This may include total quality management, culture management and matrix management, amongst others. None of these however has left behind the core tenets of Bureaucracy. Hierarchies still exist, authority is still Weber's rational, legal type, and the organization is still rule bound. Heckscher, arguing along these lines, describes them as cleaned up bureaucracies , rather than a fundamental shift away from bureaucracy. Gideon Kunda, in his classic study of culture management at 'Tech' argued that 'the essence of bureaucratic control - the formalisation, codification and enforcement of rules and regulations - does not change in principle.....it shifts focus from organizational structure to the organization's culture'.
Another smaller group of theorists have developed the theory of the Post-Bureaucratic Organization., provide a detailed discussion which attempts to describe an organization that is fundamentally not bureaucratic. Charles Heckscher has developed an ideal type, the post-bureaucratic organization, in which decisions are based on dialogue and consensus rather than authority and command, the organization is a network rather than a hierarchy, open at the boundaries (in direct contrast to culture management); there is an emphasis on meta-decision making rules rather than decision making rules. This sort of horizontal decision making by consensus model is often used in housing cooperatives, other cooperatives and when running a non-profit or community organization. It is used in order to encourage participation and help to empower people who normally experience oppression in groups.
Still other theorists are developing a resurgence of interest in complexity theory and organizations, and have focused on how simple structures can be used to engender organizational adaptations. For instance, Miner et al. (2000) studied how simple structures could be used to generate improvisational outcomes in product development. Their study makes links to simple structures and improviseal learning. Other scholars such as Jan Rivkin and Sigglekow, and Nelson Repenning  revive an older interest in how structure and strategy relate in dynamic environments.  Functional structure
In a functional structure, the division of labor in an organization is grouped by the main activities or functions that need to be performed within the...