OARS: an object-oriented architecture for reactive systems

This paper discusses an architecture designed to provide support for the development of state transition models for an object-oriented distributed environment. The state transition models can be constructed and specified hierarchically as well as derived into new classes of objects through the use of inheritance. A new concept called "exit-safe states" is introduced to assist in the specification of hierarchical state transition models. A graphical monitor to analyze the system at run time has been developed.