In both the translation industry and translation education, analytic and systematic assessment of translations plays a vital role. However, due to lack of a scheme for describing differences between translations, such assessment has been realized only in an ad-hoc manner. There is prior work on a scheme for describing differences between translations, but it has coverage and objectivity issues. To alleviate these issues and realize more fine-grained analyses, we developed an improved scheme by referring to diverse types of translations and adopting hierarchical linguistic units for analysis, taking English-to-Japanese translation as an example.