Many reports have described the application of statistical quality control (SQC) techniques to efficiently resolve issues in manufacturing. However, factor analysis can be difficult to implement for phenomena with large numbers of factors that have complex causal structures. In conventional factor analysis, factors are organized into an Ishikawa diagram considering the causal structures of the products or processes. However, these structures are frequently ignored at the analysis stage. Consequently, factor analysis becomes difficult if the causal structure is complex. Structural equation modeling is capable of considering multiple causal structures and is therefore regarded as a possible solution for this issue. However, the details of structural equation modeling are unclear since no research has been published about its application to similar issues in the general industrial field. Therefore, the details and effectiveness of structural equation modeling were identified by applying this method to factor analysis of the manufacturing processes of transmission parts.