Henry Mintzberg is an American management theorist, who has been described as a "pioneer in the study of organizations." In his book The Nature of Managerial Work, he discusses five managerial roles. Role of the manager: The manager is responsible for leading and coordinating the company's strategic planning and implementing its strategy into action. Role of the planner: A planner is responsible for developing strategies and plans that will ensure long-term success. They are also responsible for making decisions about how to allocate resources to different projects or tasks. Role of the executor: An executor is responsible for carrying out tasks assigned by others in order to complete them successfully. They are also expected to make decisions on their own about how they should carry out their duties in order to achieve success.