A new role hierarchy model for RBAC (role-based access control) is presented and its features are illustrated through examples.

Combined with the issues of private permissions, department permissions and changes of permission types, subjects of role permissions and role hierarchies are analyzed in more depth and an improved role hierarchy model for role based access control (RBAC) is introduced against the imperfections of the famous RBAC96 model.

Based on the above ideas,an improved role hierarchy model is formulated.

After analyzing we can find that these models can protect information of user and server security, and also can ensure the stability of role hierarchy in the base of amending role’s authority conveniently.

SARBAC/SARBAC-HH models are dominative in implementation of role hierarchy management by analyzing and comparing several typical role-based access control models.

In building software corporation management platform (SCMP), we proposed a new concept of capability groups with hierarchical relations.

So it is necessary to define the concepts, identities, function, nature and form of the elements in various layers, and normalize the hierarchical relations between them.

It makes full use of the hierarchical relations and the characteristics of attribution in domain ontology,meanwhile,ontology structure is gradually perfected in the process of the extraction.