Ordering food at a restaurant might be modeled as a channel based process. The thoughts concerning food preference might be seen as the source, the vocalized order comes from the transmitting mouth, the waiter's ear is the receiver, and the chef is the destination. There is a symmetrical nature to the Shannon model that is missing from this example but, nevertheless, using the Shannon model may help an individual studying restaurant operations to be able to elucidate aspects of the operation that they hadn't considered before. For example, use of this model may suggest that noise effecting the channel might be examined. A channel requires spatial or temporal distance between the sender and the receiver.
Energy is necessary to transmit the message from the sender to the receiver.
For Shannon, a channel is defined by a set of conditional probabilities that a certain message is received given what was transmitted. In cases where there is no noise, the conditional probability that a message is received given what was transmitted is simply the unconditional probability that the message is received. In noisy environments, what is transmitted is not always what is received. The hierarchical model is, in some senses, a generalization of Shannon's model of a communication system. Both provide a channel through which values may be passed.