Relocation of the Fuel Fast Fill Unit on the Komatsu PC2000 from Beneath the Engine to the Unit Stairs as an Effort to Improve Safety, Refueling Efficiency, and Reduce Production Loss Time (Case Study of Quality Control Project Implementation in the

The Komatsu PC2000 excavator operating in the AMM Pit Area at the Mifa Jobsite was equipped with a fast-fill fuel system positioned beneath the engine, exposing its components to potential damage from boulder impacts and creating accessibility challenges during refueling operations. Maintenance records from February 2024 to July 2025 documented nine system-related incidents resulting in at least 25 hours of equipment downtime, of which 16.7 hours (66.8%) were attributed to structural damage. This study evaluated the relocation of the fast-fill fuel connection point from beneath the engine to the excavator stairway area using the eight-step Quality Control Circle (QCC) methodology integrated with the Plan–Do–Check–Act (PDCA) cycle. Data were collected through maintenance records, field observations, cross-functional team discussions, Pareto analysis, Ishikawa cause-and-effect analysis, and solution-selection matrices to identify the primary causes of equipment downtime and determine appropriate corrective measures. Following the relocation, no additional fast-fill system disturbances were recorded during the specified monitoring period. For seven Komatsu PC2000 excavators, the projected operational benefits included annual savings of 638.5 equipment operating hours, a reduction in fuel consumption of approximately 76,620 liters, and a potential productivity gain of 447,125 bank cubic meters (BCM). However, these estimates were based on projected operational scenarios rather than independently verified annual performance measurements. The reported implementation cost was IDR 34,815,899 per excavator. Overall, the modification improved access to the refueling connection and potentially reduced component exposure to mechanical impacts, although its long-term reliability, safety performance, and economic benefits required further evaluation. These findings demonstrated the potential of evidence-based maintenance practices and multidisciplinary QCC methodologies to support targeted equipment modifications, improve refueling efficiency, and minimize production-related downtime in mining operations.