The relationships between the hierarchical classification based on the subjective assessment value and that based on the objective assessment value and between the safety factor based on the subjective ratio and that based on the objective ratio were investigated from the viewpoint of information entropy. In the case of the hierarchical classification, it was found that even if the subjective assessment value is divided into classes of equal width, the classes in the middle range have larger widths in the objective assessment value. This fact should be taken into account when the hierarchical classification result is discussed objectively. In the case of the safety factor, in order to set the safety factor with greater confidence, it is necessary to estimate the safety factor based not only on the old subjective ratio but also on the objective ratio converted from the subjective ratio.