STRATEGY TO INCREASE PHYSICAL AVAILABILITY OF KOMATSU HD785-7 FOCUS ON FRAME & BODY AREAS THROUGH MAINTENANCE APPROACH AND FMEA AT PT. UNITED TRACTORS SITE SATUI

Abstract

This study addresses recurring chassis failures of Komatsu HD785-7 dump trucks at PT United Tractors Site Satui, where structural cracks contributed to 40,1% of total downtime in 2023, reducing Physical Availability (PA) below the contractual target of 92%. The objective is to restore PA through an optimized maintenance strategy using the DMAIC framework. Analytical tools including pareto analysis, why-why analysis, and failure mode and effect analysis were applied to identify high-risk positions and determine corrective actions. Crack mapping was introduced to standardize inspection points, while repair and reinforcement methods were compared based on lifetime, redo rate, downtime, and cost. Results show that reinforcement extends component lifetime beyond 3.000 hours, reduces redo rates to below 15%, and provides long-term cost efficiency despite higher initial expense. The study concludes that integrating crack mapping with FMEA based decision making effectively reduces structural failures and enables PA recovery to exceed 92%, offering a replicable method that can be applied to other mining equipment models.