Application of Failure Mode and Effects Analysis to Improve Maintenance Planning at a Fertiliser Blending Plant in Enugu State

Unplanned equipment downtime at fertiliser blending plants in Nigeria's South East zone reduces operational efficiency and disrupts agricultural input supply chains during critical planting seasons. This study applies failure mode and effects analysis to the mechanical and process equipment of a fertiliser blending plant in Enugu State, with the objective of prioritising maintenance interventions and reducing unplanned downtime. The study team comprised plant engineers, maintenance technicians, and production supervisors. Equipment covered in the analysis included bucket elevators, belt conveyors, screening units, mixing drums, bagging machines, and dust collection systems. Historical maintenance records over a four-year period were analysed to identify failure frequency, mean time between failures, and failure modes. Risk priority numbers were calculated for each identified failure mode based on severity, occurrence, and detectability ratings assigned by the team. A total of 68 failure modes were identified across all equipment categories, with risk priority numbers ranging from 8 to 432. The five highest-priority failure modes were bucket elevator chain elongation, screening mesh blinding, bagging machine weighing cell drift, mixing drum bearing seizure, and dust collector filter bag rupture. Revised maintenance strategies, including condition-based monitoring intervals and spare parts stocking targets, were developed for each critical failure mode. Post-implementation simulation indicated a projected 29% reduction in unplanned downtime. The study provides a replicable failure mode and effects analysis methodology for Nigerian fertiliser blending plants. Keywords: failure mode and effects analysis, FMEA, fertiliser blending, maintenance, Enugu State