<![CDATA[Background: Power plant overhaul projects play a critical role in maintaining project performance targets (quality, cost, and schedule) and operational reliability indicators, including efficiency, Equivalent Availability Factor (EAF), and Equivalent Forced Outage Rate (EFOR). However, many overhaul projects still experience difficulties in achieving planned targets due to ineffective project management practices. Objective: This study aims to identify the dominant causal factors contributing to the failure of overhaul performance targets and develop managerial improvement strategies. Methods: A mixed-method approach was applied through a questionnaire survey involving 100 respondents (50 owners and 50 contractors), Relative Importance Index (RII) analysis for factor prioritization, tree diagram-based Root Cause Analysis (RCA), comparative analysis of actual project performance data, and Focus Group Discussion (FGD) validation. Results: The Serious Inspection (SI) overhaul project of Steam Power Plant Unit 3 at PT XYZ failed to achieve five of six established performance indicators. The findings revealed that performance failures were caused by systemic interactions among planning, inventory management, resource management, and team execution management. Planning and inventory management were identified as the most dominant factors, resulting in schedule delays, cost overruns, incomplete work before unit return-to-service, and suboptimal operational performance, reflected by an EAF of 88.5% and EFOR of 11.5%. Conclusion: This study recommends risk-based integrated planning, criticality-based inventory optimization, competency improvement, and stronger team coordination to enhance the effectiveness and reliability of future power plant overhaul projects.]]>
