Modeling the Impact of Raw Materials Suppliers Competition on Procurement Costs in the Green Closed Loop Supply Chain

Nowaday, competition affects all processes of production and supply of products, so that most manufacturers and suppliers of materials can not have a market share if they do not think about increasing quality and reducing prices, so in this article the effect of competition of raw material suppliers on supply and procurement costs Materials for manufacturers in a multi-product supply chain Green closed loop is examined. First, competitive modeling in the supply process between raw material suppliers in different groups is done by estimating the demand for each of the chain products and setting the demand quantity parameters of each product. And the rate of return flow in the competitive model using the principles of game theory to find the equilibrium point of competition among each group of chain suppliers. Then by solving the model of changes in the cost of supply and goods for manufacturers and suppliers of chain raw materials in two cases The existence of competition and its absence are compared and decisions are made.