OPTIMASI PEMELIHARAAN GAS TURBINE COMPRESSOR BERBASIS RELIABILITY AVAILABILITY MAINTAINABILITY (RAM) DAN COST OF UNRELIABILITY (COUR) ANALYSIS

Abstract

The Gas Turbine Compressor (GTC) plays a strategic role in sustaining oil and gas production processes, yet its vulnerability to mechanical failures often results in significant downtime. This study aims to evaluate the performance of the GTC unit at PT XYZ using the Reliability, Availability, and Maintainability (RAM) approach, along with Cost of Unreliability (COUR) analysis, to formulate a more effective maintenance strategy. The analysis was conducted based on historical failure and repair data for critical components—namely shaft coupling, bearing, steam filter, and seal lube oil—collected over the period 2017 to 2021. Failure distribution patterns were identified using the Anderson-Darling test, with results indicating that Weibull and Lognormal distributions best fit the observed data characteristics. The findings revealed that the shaft coupling and seal lube oil exhibited low reliability and high Mean Time to Repair (MTTR), while availability trends among components were relatively consistent. COUR analysis identified the shaft coupling as the largest contributor to financial loss due to downtime, amounting to approximately IDR 1.12 billion during the observation period. Based on the failure mode consequences and the company’s target system reliability of 97.5%, a Reliability Centered Maintenance (RCM) strategy was proposed, recommending optimal maintenance intervals between 1,500 to 3,000 operating hours for the critical components.

Keywords: Gas Turbine Compressor, Reliability Availability Maintainability (RAM), Cost of Unreliability (COUR), Maintenance Optimization, Operational Efficiency