According to Herbert Simon, communication is a process whereby decisional promises are transmitted from one member of an organization to another. Data and information are transmitted to the decision maker through the communication channels. Shannon and Waever model of communication channel involves a source, an encoder, message channel, a decoder, a receiver and feedback.
Source is a member with ideas, information and a purpose for communication. Communication process involves something being sent to a receiver. What receiver does with the communicated message is the vital part of the whole system. Simon says, there is an informal system of communication in an organization based on social relations such as friendship. It is termed as 'grapevine' and is a valuable measure of public opinion in an organization.
From 'grapevine' the administrator can understand the subjects of interest to organization members and their attitude towards certain topics. Organizations use sophisticated communication systems such as computers and internet for decision making.