Models with network duals

It is pointed out that a number of practical problems can be formulated as linear programmes whose duals are network flow models. The interpretation of these networks in relation to the original problem can be highly illuminating. If, as is frequently the case, the objective of the original problem is monetary, the network dual concerns the optimal pattern of re-allocation of money. It is suggested that the conceptual simplicity of a network makes this an attractive way to view problems as well as indicating efficient computational procedures.