Three central schools of thought form the central knowledge on change management. These schools are:
The individual perspective consists out of two primary views. Behaviourists claim that Individuals are simply a sum of their parts. The behaviour of people can be influenced by identifying the individual parts and influence behaviour by external stimuli. Gestalt-Field psychologists however argue that individuals behaviour is derived from coexisting and interdependent forces that are acting upon the individual. Change can be achieved by gaining or amending insights, outlooks, expectations or thought patterns. In other words, the interpretation of individuals is an important factor of change that Gestalt-Field theorists believe exists and behaviourists do not.
Summarising. Behaviourists seek to achieve organisational change by changing the external stimuli. Gestalt-Field psychologist achieve organisational change to ensure individuals learn about themselves, and through this change, their understanding of themselves and their work context.
Rather then brining change via individuals the group dynamics school wants to bring change via groups. According to Lewin is the rationale behind this that - as people work in groups, individual behaviour must be seen, modified, or changed in the light of groups' prevailing practices and norms. The main method of organising change according to this group is to influence the groups' norms, roles, and values.
Critical distinction for this group is that between implicit and explicit norms. Explicit norms are formal and written rules which are known by and applicable for all. Implicit norms are informal and unwritten. Individuals might not even be consciously aware of them. However, implicit norms haven been found vital in dictating the actions of group members.
The open systems school seeks to view and understand organisations in its entirety. This school sees Organisations as interconnected sub-systems. Key perspective is that organisations are not simply systems in isolation, but the are open for internal and external influences.