A Cost-Based Decision Framework for Multi-Item Single-Supplier Inventory Control

Abstract

Inventory control in manufacturing systems frequently involves managing multiple raw materials from a single supplier. Independent ordering policies in these settings often lead to higher inventory costs. This study presents a cost-based decision framework for determining optimal ordering policies in multi-item, single-supplier inventory systems. The framework integrates the Economic Order Quantity (EOQ) and Economic Order Interval (EOI) models to evaluate both independent and coordinated ordering strategies under deterministic demand conditions. A numerical example, based on a representative consumer goods manufacturing scenario, illustrates the application of the framework. Results demonstrate that coordinated ordering under the EOI policy achieves lower total inventory costs than independent EOQ-based ordering. Sensitivity analysis shows that variations mainly affect the cost-benefit of coordinated ordering through ordering costs and remain relatively stable despite demand fluctuations. This framework provides practical guidance for decision-makers aiming to implement cost-effective inventory ordering policies