2.2.3 Current Research Activities

The current research activities [LMSY 95,LuSl 97d,LuSl 97b,LuSl 97c,LSY 97] combine policies with a role concept of classic Role Theory. Affiliation to a role is represented by being member of a role domain. Policies apply to this domain. Policies are not entirely sufficient to model all requirements. Therefore, research is carried out on interaction protocols (e.g. delegation of tasks) and concurrency constraints (e.g. coordinating access to shared objects). Very recently, the domain model has been suspected of not being sufficient enough for modelling complex role attributes and relationships. The use of role classes with inheritance is investigated at the moment.