This study presents an integrated financing model for the multi-period and multi-product production planning problem, focusing on small and medium-sized enterprises (SMEs) within the supply chain. The rapid globalization and intense competition in the manufacturing sector underscore the importance of efficient production planning and control. Effective production planning integrates various production activities to minimize unproductive resource use, balancing inventory, production costs, and service levels. The study addresses a significant challenge SMEs face: securing adequate financing for their operations. Established companies often have fixed assets that can be used as collateral for loans, whereas SMEs, especially startups, struggle due to limited fixed assets, facing high interest rates if they can secure loans. Additionally, SMEs often have weak bargaining power and limited credit histories, making it difficult to obtain trade credit. To tackle these issues, this research develops a mathematical model that integrates financial flows with physical production flows within the supply chain. The proposed model leverages accounts receivable financing, wherein financial institutions discount receivables to provide necessary funding with fewer collateral requirements. This approach addresses SMEs' liquidity needs and stabilizes their profitability and operational efficiency in uncertain environments. The study employs fuzzy Delphi and hierarchical analysis to identify key parameters and assumptions for the financial and production planning model. It then tests the model using real-world data from SMEs in the sugarcane industry, demonstrating its effectiveness in reducing overall system costs and enhancing financial stability.