Scenario-Based Comparison of Calculated Inventory Costs Using Economic Order Quantity and a Just-in-Time Replenishment Formulation in a Textile Company

Inventory-policy decisions require a distinction between calculated scenario costs and realized post-implementation performance. This study compares two inventory-cost scenarios for PT XYZ, a textile manufacturer, using 2022 company records for fabric, elastic, and thread. The primary analysis applies the Economic Order Quantity (EOQ) model and a Just-in-Time (JIT) replenishment formulation to estimate order quantities and inventory costs from the recorded inputs. Questionnaire responses from 50 employees in the Raw Material Warehouse Department and Production Control Unit are analyzed separately as contextual evidence on inventory-control practices and perceived cost efficiency. The operational calculations yielded total inventory costs of Rp62,591,402 for the EOQ scenario and Rp18,146,228 for the JIT scenario, a difference of Rp44,445,174 or 71.01% relative to the EOQ total. Because the two scenarios do not capture every logistics, shortage, transition, and supplier-coordination cost on an identical cost boundary, the difference is interpreted as a calculated scenario advantage rather than realized post-implementation savings. Before implementation, PT XYZ should apply a common total-cost boundary and evaluate JIT feasibility using supplier reliability, service-level performance, and organizational-readiness indicators.