REDUCTION OF MEAN TIME TO REPAIR (MTTR) OF KOMATSU BULLDOZER BY FAILURE MODE EFFECT ANALYSIS (FMEA) APPROACH AT PT XYZ IN TANJUNG ENIM JOBSITE

Abstract

PT XYZ's Tanjung Enim operation faces critical maintenance challenges with Komatsu bulldozer fleet consistently exceeding the 4-hour MTTR target. All three bulldozer models (D375A-6R, D155A-6R, and D85ESS-2) demonstrated excessive repair times of 4.6-5.6 hours, representing 15-40% deviations above target performance. This research aimed to reduce MTTR through systematic application of Failure Mode and Effect Analysis (FMEA) integrated with DMAIC framework, targeting minimum 20% MTTR reduction. A mixed-methods approach was employed over four months, analyzing 588 maintenance events with cross-functional teams of 18 stakeholders. FMEA implementation used modified RPN calculation emphasizing repair time impact. The integrated FMEA-DMAIC approach achieved 23.4% average MTTR reduction, exceeding the 20% target. Individual model improvements were: D375A-6R (28.6% reduction, 5.62→4.01 hours), D155A-6R (29.8% reduction, 5.38→3.78 hours), and D85ESS-2 (13.1% reduction, 4.58→3.98 hours). FMEA identified 47 failure modes with 10 critical modes (RPN >200), led by hydraulic pump contamination (RPN=504). Equipment availability improved from 94.2% to 97.1%, while process capability (Cpk) increased from 0.31 to 1.46. Implementation generated substantial annual savings with 650% ROI and 3.1-month payback period.