Track: Engineering Management

Abstract

The purpose of this paper is to outline areas of improvement to optimize maintenance strategy of Load Haul Dumpers (LHD) fleet by determining factors influencing reliability and maintenance cost of LHD fleet used at the underground hard rock mine in South Africa. The stage of product lifetime distribution in which LHD fleet fall under is being analyzed. The study collects operational data comprising of maintenance and financial values. Pareto analysis is performed in order to determine the top twenty subsystems contributing eighty percent of factors affecting LHD fleet reliability. Weibull analysis is also performed to determine the stage of product lifetime distribution in which LHD fleet fall under. The results from the Pareto analysis indicates that fittings and hoses, electrical systems, air conditioning system, engine, brakes and transmission formed part of the top twenty percent which accounted for eighty percent of LHD fleet failures. Pareto analysis also outlined the top twenty percent of subsystems which accounted for eighty percent of total maintenance spend. Tyres also forms part of the top twenty percent which accounted for eighty percent of both total maintenance spend and LHD fleet failures. The LHD fleet is in the middle of the wear-out stage as determined using the Weibull distribution. The method of Pareto chart for determining subsystems which accounted for eighty percent LHD fleet failures and maintenance spend uses real case study data. The Weibull distribution also used real case data. The research study used a twelve month period for both maintenance and cost data.