The term paradigm comes from the greek word meaning pattern or example. The five paradigms are classical, processual, systemic, evolutionary and cms.
The classical approach is the oldest approach - military
inspired. It focuses on profit maximising, relying on rational methods as well as being the most dominant of the approaches. The environment around them is believed to be dynamic although it is also seen as mostly predictable and can be controlled.
Evolutionists believe that environmental changes are too fast to be predicted in advance therefore long term planning is not needed and you must focus on the short term. It is similar to classical as it sees profit maximisation as important yet is doesn't agree with rational planning.
Theorists such as Hannan and Freeman takke this approach as they believe that the environment is typically too implacable and too unpredictable to anticipate effectively.
The processual approach was influence by Mintzberg who believes in the idea of raitonal economic man or markets being responsible for maximization. They believe that rational decision-making is imperfect and the believe that strategt comes from mistakes, learning and compromise.
The systems approach is a lot less pessimistic then the processualists about peoples ability to carry out rational planning yet are more optimistic then evolutionists. They do not focus on profit maximisation but focus on proffessional pride, managerial power or national patriotism. They often stray from the rules of textbooks because they are irrational but conform to the culture in which they work.
CMS is very similar to the processual approach but for CMS, politics and ethics manage. Change must be more democratic and they focus on the culture and manipulation of ideas.