Root cause analysis of bearing installation failure in a precision manufacturing company using an integrated FMEA–FTA framework

A precision manufacturing company is committed to delivering high-quality, precise products that meet customer expectations and help it remain competitive in the global market. During the implementation of the Agile Tool project, several defects were identified, resulting in losses for the company. The number of defects produced is quite detrimental to the company because it can increase workload, operational costs, and production time, resulting in delays in the delivery of other scheduled production. This study was undertaken to analyze the factors contributing to the most significant defect in the production of Agile Tools, specifically the gearbox component. Utilizing the Failure Mode and Effect Analysis (FMEA) method to identify failures and employing Fault Tree Analysis (FTA) to ascertain the root cause of the primary failure factor. The highest RPN was found for bearings that cannot be installed, reaching 165.75, with various causes identified across the man, method, machine, and material domains. Based on the categorized aspects, the causes of the highest defect rates in the gearbox include new operators unfamiliar with the machine, human error, inappropriate machine speed settings, lack of machine maintenance, lack of machine cleanliness, and castings.