Analysis of Factor Causing Downtime on Drum Coolers at PT X

Abstract

This study aims to explore the various factors causing downtime in the Cooler Drum machine at PT X and identify the main factors contributing to the machine's reliability. The method used was a descriptive quantitative approach, collecting data through field observations, interviews with technicians, and downtime logs. The data were analyzed using Failure Mode and Effect Analysis (FMEA), Fishbone Diagrams, and Pareto Diagrams to identify the root causes of failures. The findings of this study indicate that Plant NPK 2 performed the lowest, with 85.74 hours of downtime, an MTBF of 866.48 hours, and an MTTR of 12.24 hours. Meanwhile, Plant NPK 4 performed the best, with only 4.16 hours of downtime, an MTBF of 2465.39 hours, and an MTTR of 1.39 hours. Based on the Pareto analysis, approximately 75% of the total downtime was caused by four main factors: bearing damage, chain drum impact, rubber inlet leaks, and trunion shaft fractures. The FMEA analysis showed that the fluid coupling and shaft trunion had the highest RPN values ​​(144 and 90), indicating a significant risk of failure. The Fishbone Diagram results indicated that machine factors and maintenance methods were the most important causes, followed by human, material, and environmental factors. Recommended improvements include optimizing preventive and predictive maintenance, improving operator discipline, ensuring the availability of critical spare parts, and controlling the work environment to reduce failure rates and improve operational continuity. This study confirms that implementing an effective maintenance program has a direct impact on reducing downtime and increasing company productivity.