Exploiting Inheritance in Modeling Architectural Abstractions

Formal (mathematical) modeling of a specification provides an unambiguous representation that allows for rigorous analysis and reasoning over properties. Architecture descriptions define an abstract representation of a system component that is amenable to formal modeling. Using formal modeling within this context provides a basis for integrated system descriptions and analysis, as well as a basis for guaranteeing properties of applications. Missing from the formal modeling of architectures, however, is the notion of inheritance. Representations that include inheritance could provide for a taxonomy of architecture abstractions that model generic classes that can be inherited by more specific classes. Such a taxonomy would include reusable templates and abstract properties that can be inherited to relieve some of the burden of repeated specification and proof. Further benefits can be achieved when designing an integrated system comprising multiple architecture descriptions. By modeling an integrated system at a high level of abstraction, it is easier to initially derive and analyze properties. If the low level, more detailed system models can inherit the high-level specification, then the result is a savings in time and effort, along with a reduction in error (Hasler et al., 1998). This paper describes a Distributor Controller, a type of controller component (Keshav and Gamble, 1998) that requires decisions to be made on incoming data, such as which data to pass and which known components should receive it. The Distributor Controller is an integration component that can link two heterogeneous components (Stiger and Gamble, 1997) or two complete software systems (Stiger et al., 1997).