Optimization of Sand Material Inventory Control to Minimize Costs at PT XYZ.

Abstract

General Background Inventory management inefficiencies can lead to either stock accumulation or material shortages if ordering relies purely on subjective estimation. Specific Background PT XYZ operates in the production and distribution of concrete and experiences fluctuating sand material arrivals that complicate optimal order determination. Knowledge Gap Comprehensive quantitative evaluations combining Economic Order Quantity (EOQ), Safety Stock (SS), and Reorder Point (ROP) for sand inventory in concrete manufacturing require systematic validation. Aims This study analyzes sand material control using EOQ, Safety Stock, and ROP methods based on operational data from November 2025 to April 2026 to minimize costs and prevent imbalances. Results The optimal ordering quantity is 2,827.05 tons per order with a frequency of 4 times per period, backed by a safety stock of 2,030.54 tons and a reorder point of 2,339.24 tons, yielding an efficient Total Inventory Cost (TIC) of Rp41,675,539. Novelty The integration of probabilistic safety stock formulas with EOQ and ROP parameters provides an optimized inventory framework tailored specifically to concrete production requirements. Implications Implementing these quantitative methods successfully prevents material imbalances while maintaining continuous and efficient operational continuity for the company. Key Findings Highlights The optimal ordering quantity for sand material was calculated at 2,827.05 tons per order with an ideal frequency of 4 times per period. A safety stock of 2,030.54 tons and a reorder point of 2,339.24 tons were established to mitigate supply uncertainty and delivery delays. The integrated inventory approach successfully minimized expenditures, achieving an efficient Total Inventory Cost of Rp41,675,539. Keywords Inventory Control, Economic Order Quantity, Reorder Point, Safety Stock, Material Management