A Two-Echelon Inventory Model for Growing and Perishable Products Considering Preservation Technology, Inventory Level and Freshness-Dependent Demand, and Carbon Tax Regulation

Food waste and loss are significant global issues, with substantial economic, social, and environmental impacts. The United Nations estimates 1.05 billion tons of food are wasted annually, costing around USD 1 trillion. Indonesia faces similar challenges, with food waste contributing to 4-5% of its GDP and significantly adds to greenhouse gas emissions, accounting for 7.29% of the country's annual emissions. A major source of waste is perishable products, necessitating improved inventory management. Perishable products are often derived from growing items. Traditional Economic Order Quantity (EOQ) models, which optimize order quantities, typically do not account for the deterioration in perishable products or weight changes in growing items. Recent research has sought to refine these models, incorporating factors like carbon emissions, preservation technology, and demand rates linked to inventory levels and freshness index, aiming to reduce waste and maximize profit. The suggested model is solved analytically using the software Mathematica 11.2. Furthermore, numerical examples and sensitivity analysis are used to demonstrate how significant factors affect operational choices. Result reveal how some parameter impact optimal replenishment cycle length, preservation technology cost, and total profit.