A failure mode analysis approach in an engine assembly plant within the framework of iatf 16949 and apqp

In this thesis study, the problems encountered in the assembly processes of internal combustion engines at a Turkish automotive company between 2022 and 2024 were analyzed within the scope of the IATF 16949 quality standard, which is recognized by leading European automotive manufacturers, and improvement efforts were carried out. To examine the problems in assembly processes in detail, PFMEA, 8D, and root cause analysis methods were utilized. The study specifically focused on oil leakage and valve seizure issues occurring in the cylinder head. Functional analysis, risk assessment, and failure analyses were conducted for these problems. As a result of the analyses, defects were identified as being caused by factors related to parts, environment, transportation, methods, fixtures, and operators. Action plans were developed to eliminate these defects and minimize their occurrence probability. As a result of the implemented PFMEA actions, defect rates were minimized, and a 4.5% improvement in OEE rates was achieved.