In some industries, incident cases have been collected positively to grasp the seeds of future accidents. However, as the number of incident reports becomes larger, the safety manager will find it difficult to continue analyzing all seeds. In order to solve the problem, we intend to propose a way of evaluating the tendency of the human error seeds, which are called PSF (Performance Shaping Factors). Firstly, PSF Check Sheet is used to collect incident cases with PSF around them. Secondly, the book of the PSF Check Sheets is summarized through Comment Database into an Assessment Sheet, which contains a graph of the PSF tendency and comments about estimated latent problems in the work environment. As a result of our case studies, the validity of the method was confirmed, and advantages and disadvantages are found out. It can be installed effectively and promote safety activities.