The supply chain network with capacity constraints of manufacturers and retailers is considered.The linkage between supply chain network equilibrium and transportation network equilibrium is investigated.By analyzing the relationships among the manufacturers,retailers and consumers in the supply chain network and their own decisions concerning maximum profits,a combined variational inequality for the supply chain network equilibrium mode is proposed.Then an equivalent supernetwork of the supply chain network is constructed by adding additional links which denote the producing of manufactures and the handling of retailers.By the supernetwork,the supply chain network equilibrium model can be reformulated as a transportation network equilibrium model.Equivalent mathematical programming is,therefore,obtained based on the principle of a Wardrop user equilibrium.The corresponding Lagrange multiplier of the capacity constraints can be explained as the extra cost of marginal production when capacity is exceeded.A numerical example is given to illustrate the rationality of the model and the validity of the results.
