This study examines the supply chain of Tehran Municipality's fruit and vegetable markets, focusing on reducing costs in direct supply markets. The research aims to develop a model of key factors affecting Tehran Municipality's fruit and vegetable supply chain and evaluate corrective policies using system dynamics modeling." The statistical population comprises professionals from Tehran Municipality's direct supply markets and central market with bachelor's degrees or higher in agriculture, finance, business, and related fields. Expert gardeners were selected from among exemplary gardeners across different geographical locations, holding at least a bachelor's degree. The study analyzed the distribution data of direct supply markets over a 12-month period in 2019." The research employed system dynamics methodology using Vensim software to analyze system behavior, focusing on the complexity of relationships between multiple variables, feedback loops within the system, and the cumulative or flow nature of variables. Model simulation and implementation of two scenarios revealed that the third level of the chain (retail) could be optimized through pre-sorting before delivery to direct supply markets, thereby reducing waste costs." Reducing blocked inventory leads to decreased storage costs, which subsequently resulted in increased market share variability."