Even when an individual's actions act as a trigger and an accident resulting from human error occurs, the background can conceivably have been problems inherent in the organization, i.e. its systems and climate in terms of safety. Systematic management is thus essential to prevent human error. Therefore, we developed a human factor analysis method to pursue the underlying causes of human error. This paper report on the present status of human factor analysis in relevant railway-related companies and provide an outline of the analysis method, which consists of a three-step procedure. Using each step it is possible to perform analyses based on diverse viewpoints with reference to human factor models and the PDCA cycle.