A New Stock Control Model Proposal for an Inventory System Allowing Internal Audit, Carbon Emissions, and Repair

This study develops a profit maximisation model for inventory systems operating under environmental regulations and governance requirements. The model determines the optimum order quantity and order delay level by combining the costs of defective products, repairs, stock shortages, carbon emissions, and internal audits. It shows that emissions and audit costs affect inventory replenishment policy, reducing the annual order quantity by 7.52%. Sensitivity results indicate that emission-related parameters primarily affect inventory replenishment, while audit-related parameters alter profitability without destabilising the structure of the optimum policy. The study provides an analytical decision support tool for balancing inventory profitability with environmental compliance and governance-focused auditing.