MODELING OF EQUIPMENT MAINTENANCE MANAGEMENT SYSTEM IN SELECTED GRANITE QUARRIES IN SOUTH-WESTERN NIGERIA

Abstract

Poor performance of granite aggregate quarries is a big challenge to the mineral industry in Nigeria. It threatens the future prosperity of the industry and granite aggregate supply to meet the ever increasing demand for infrastructural development projects. One major factor impacting on the reliability of quarries is the maintenance management system of the quarry equipment. This work attempts to model equipment maintenance management system of the selected quarries (Geoworld, OrientalFemab Mining (OFM) and Construction Products Nigeria Limited (CPN)) in part of South- west Nigeria. Four critical equipment (Drill Rig, Hydraulic Excavator, Dump Truck and Crushing Plant) employed in the quarries were studied and compared based on performance and maintenance data of the equipment collected for a period of one year from observations; equipment monitoring; experiments; interview and questionnaires. Maintenance management audit of the quarries was carried out in relation to five basic elements of maintenance management system (resource management, information management, preventive maintenance and equipment technology, planning and scheduling and maintenance strategy). The performance result of the equipment showed varying trend which depicts the inherent technical flaws in the selection and acquisition of the equipment and ineffective maintenance management of the equipment. Pareto analysis of the failure frequencies of the upstream equipment showed similar trend for Geo world and OFM quarries where hydraulic excavator has the highest failure frequency followed by Drill Rig unlike CPN quarry that has dump truck with the highest failure frequency. However, maintenance performance indices of the quarries showed that about 21% of the downtimes are caused by equipment breakdowns; 19% of production cost is spent on maintenance and about 14% is spent on maintenance per ton of granite aggregate sold. SWOT analysis from maintenance management audit revealed low rating (about 50% as compared with 85% for global best practice) for the elements of maintenance management which further confirmed the inappropriate design integrity of the quarries and poor maintenance management system that informed the usual longer payback period of quarry projects in Nigeria. ‘SWOT CLOCK’ Strategic Behaviour Model was adapted to suggest a rationalistic typology for managers and decision makers in considering the quarries’ strategic direction on equipment maintenance based on the interaction between the quarries capabilities and resources from the view point of strengths and weaknesses (SW) and between the opportunities and threats (OT) identified in the quarries environments. Findings show that improvement strategies adopted will impart positively on the areas of deficiencies of the investigated quarries by moving them from state of survival to response and growth respectively.