evaluate the role of policies in the sustainability of the supply chain through a comprehensive mathematical approach

This study has two policies to support supply chains. in the first model, three types of subsidies are provided for each supplier. in the second model, the government enters the chain directly by creating an integrator facility, which is responsible for packaging and coordination between facilities, and assumes the cost of packaging, and by merging publications together in one package, reduces the number of submissions and it supports the supply chain. for each of the above cases, a mathematical model was defined and a case study was conducted for 6307 customers and 119 districts of tehran. according to the output of the models, the profit of each supplier including subsidies was more than the second model in the first model. however, the amount of subsidies paid in the first model is much higher than in the second model. by considering this issue and eliminating subsidies from profit calculations of the two models, the second model showed a more favorable performance in equal and full welfare in all regions. however, the first model had a better performance in conditions with different welfares in various regions. according to the results, in addition to subsidies, the government must enact laws that oblige publishers to complete welfare.