IMPROVING COOLING SYSTEM RELIABILITY IN MOTOR GRADERS: A FIELD IMPLEMENTATION OF DMAIC AND FMEA

Abstrak

Engine overheating is a continual reliability issue in heavy machinery, especially motor graders functioning in arid mining conditions. This study presents a practical application of the DMAIC methodology integrated with Failure Mode and Effects Analysis (FMEA) to enhance the reliability of cooling systems. The baseline assessment revealed overheating-related failures that resulted in an average downtime of 30.3 hours during the evaluated period. FMEA during the Analyze phase highlighted critical failure modes in the radiator: the radiator tube RPN decreased from 392 to 96 (~75%), and the radiator fin RPN decreased from 336 to 84 (~75%) following corrective measures. Key improvements comprised installation of an automatic radiator washing system and integration of IoT-based sensors for continuous monitoring of upper–lower tank temperature differential (ΔT) and transmission filter pressure (ΔP). (Note: continuous ΔT data were not available before implementation; the deployed system established continuous ΔT/ΔP monitoring with sensor accuracy ±2 °C and predefined operational thresholds—ΔT target 8–15 °C, ΔP tolerance 4 bar.) Field monitoring demonstrated elimination of overheating-related downtime (30.3 → 0 hours) during the observation period. The Control phase instituted standardized inspection forms linked to corrective-action recommendations to sustain gains. Results indicate that combining DMAIC and FMEA with IoT-enabled monitoring delivers a practical, quantifiable approach to improve cooling system reliability in motor graders.

Kata kunci

• Cooling System
• DMAIC
• FMEA
• Mining
• motor grader