Optimization of Pc500 Unit Rolling to Eliminate Double Cost at PT Antareja Mahada Makmur Jobsite Mifa Bersaudara

Abstract

Uneven operating hours among rented excavators can result in standby charges despite adequate overall equipment utilization, thereby increasing operational costs in mining activities. This study aimed to identify the causes of hour meter imbalances and evaluate an equipment rotation mechanism for eleven PC500 excavators at PT Antareja Mahada Makmur, Mifa Bersaudara Jobsite, under a contractual minimum requirement of 398 operating hours per unit per month. A Quality Control Circle (QCC) approach incorporating the Plan–Do–Check–Act (PDCA) cycle was employed. Operational records from January to May 2026 were used to establish baseline conditions, while corrective measures were implemented and evaluated during June and July 2026. A fishbone diagram analysis identified insufficient supervisory monitoring and the absence of standardized guidelines for equipment rotation and activity allocation as the primary contributing factors. The interventions included routine operational briefings, systematic hour meter monitoring, an activity monitoring dashboard, and a rotation priority matrix developed using existing resources. Excess standby costs decreased from a peak of USD 6,528 in March to USD 145 in June and were eliminated entirely in July, when average operating hours reached 481 per unit. These findings demonstrated that prioritizing underutilized excavators could effectively minimize additional charges resulting from uneven equipment utilization. The interventions required no additional expenditure and were subsequently formalized through a standard operating procedure (SOP). The study concluded that an operating-hour-based equipment rotation strategy improved operational cost control and resource utilization, although a longer observation period is necessary to evaluate its long-term sustainability.