DEMAND-DRIVEN MATERIAL REQUIREMENTS PLANNING (DDMRP) FOR COAL INVENTORY CONTROL TO MITIGATE SUPPLY CHAIN UNCERTAINTY

Abstrak

Abstract Upstream logistical uncertainty in the primary energy supply chain represents a critical challenge for nationally vital facilities in ensuring the continuity of electricity generation. PT XYZ faces fluctuations in barge arrivals, resulting in substantial physical coal supply deficits and declining safety stock levels. This study aims to design a proposed adaptive coal inventory control system using the Demand Driven Material Requirements Planning (DDMRP) method to mitigate supply chain uncertainty, with a focus on physical quantities (tonnage). The study employed a quantitative descriptive method with a system design approach to develop a proposed DDMRP application based on operational data from 2025. The DDMRP implementation process comprises Strategic Positioning, Buffer Profiles and Levels, Dynamic Adjustments, Demand Driven Planning, and Visual Execution. The results show that positioning the coal yard as a strategic decoupling point can serve as a separation point between external supply uncertainty and internal consumption requirements. Based on an Average Daily Usage (ADU) of 11,169 tons and a Decoupled Lead Time (DLT) of 12 days, the proposed dynamic buffer level parameters consist of a Top of Red of 42,736 tons as the minimum critical level, a Top of Yellow of 176,768 tons as the replenishment threshold, and a Top of Green of 219,503 tons as the maximum inventory level. Overall, the proposed implementation of DDMRP provides a more adaptive inventory control mechanism for responding to changes in demand and supply uncertainty, supporting material flow stability, and helping to control the risks of stockouts and excessive coal accumulation. Keywords: Supply Chain Management, Inventory Control, DDMRP, Coal, Material Flow