This paper addresses the optimization of material supply and handling using simulations. The primary objective is to reduce loader downtime by improving raw material procurement and revising the work schedule for material delivery and loader operations. Through the adjustments in the scheduling of raw material deliveries, excessive idle times of handling equipment are minimized. A simulation model is designed to compare the current state with the proposed optimized scenario. The reorganization reduced loader downtime by improving raw material procurement. The simulation results indicate a decrease in loader downtime, from 33% to 13% of total available time. The analysis of storage box occupancy reveals a notable increase in supply efficiency at the outdoor landfill. Adjustments enable the delivery of larger quantities of gypsum within shorter timeframes, maximizing stored material without exceeding storage capacity constraints.