This chapter of the book "The Functions of the Executive," by Chester I. Barnard (1938), focuses on the functions of the executive organization as a whole, which exists exclusively for the coördination of the efforts of the entire organization. Barnard explains that the functions of executives relate to all the work essential to the vitality and endurance of an organization. Overall, the executive functions serve to maintain a system of coöperative effort. The essential executive functions found in complex organizations are: (1) to provide the system of communication; (2) to promote the securing of the personal services that constitute the material of organizations; and (3) to formulate and define the purposes, objectives, and ends of the organization. Since the elements of organization are interrelated and interdependent, so too are executive functions; nevertheless they are subject to considerable specialization and as functions are to a substantial degree separable in practice.