Reliability Optimization and Component Replacement Scheduling for Compressed Air Systems in Indonesian Navy PKR-Class Vessels Using FMECA and Weibull Analysis

Abstract

Compressed air systems are critical auxiliary systems aboard Indonesian Navy PKR-Class vessels, providing essential compressed air for main engine starting and various operational functions. This study addresses the frequent failure rate of compressed air systems, which experiences approximately 2 failures per 100 operational hours, significantly impacting vessel operational readiness. A comprehensive reliability optimization approach was developed by integrating Failure Mode, Effects, and Criticality Analysis (FMECA) with Weibull distribution analysis to identify critical components and determine optimal replacement intervals. Multi-expert assessment involving four independent evaluators identified five critical components from 14 assessed components: Lamellar Valve (RPN=8.14), Solenoid Valve 2nd stage (RPN=7.64), Solenoid Valve 1st stage (RPN=7.48), Safety Valve (RPN=7.16), and Non-Return Valve (RPN=6.99). Pre-optimization reliability analysis revealed critically low reliability levels ranging from R(t)=0.434 to R(t)=0.533. Through optimization using three-parameter Weibull distribution and Excel Solver, component-specific replacement intervals were established ranging from 145 to 457 days, achieving post-optimization reliability levels exceeding R(t)=0.95 for all critical components. Economic analysis demonstrated cost-effectiveness with Cost-Benefit Ratio (CBR) values below 1.0 for all components, indicating 20-33% cost savings compared to reactive maintenance approaches. The optimized maintenance strategy projects an 84.9% reduction in annual maintenance costs, from IDR 339,427,200 to IDR 51,426,953 per vessel, while improving system availability from 92% to over 99%. This research contributes a practical, data-driven framework for naval vessel auxiliary system maintenance optimization, demonstrating significant economic benefits and operational reliability improvements applicable to maritime defense operations.