According to Chester I. Barnard, executives are critical to an organization because of their leadership function, which includes communication, purpose, and cooperation. Barnard believed that communication is the fundamental mechanism that facilitates goal-reaching activities. He also believed that communication is a complex process that involves understanding, interpreting, and acting upon information.

Barnard's summary of the functions of the executive includes:

• Establishing and maintaining a system of communication
• Securing essential services from other members
• Formulating organizational purposes and objectives
• Managing people and making sure they do their jobs

Barnard also believed that executives serve three basic functions in maintaining the cooperative system:

• Maintaining and developing a system of communication
• Inducing individuals to join the organization and contribute to its mission
• Defining the purpose and objectives of the organization

Barnard believed that the extent to which workers willingly cooperate in an organization depends on the workers' perception of executive authority. He also believed that individuals join groups and organizations because they are limited in fulfilling their needs individually due to various factors, such as physiological, geographical, and psychological constraints.

Barnard (1886–1961) is best known for his book The Functions of the Executive, which had a large effect on the evolution of management thought.