Exoskeletal software

The author advocates the use of a separate and explicit structural language to describe software architectures. The structural nature makes it amenable to both textual and graphical description. Since it is a language, it can be used to support general descriptions and to provide the framework for checking interconnections. In addition, it can be used to generate and manage the system itself. This approach, initially under the guise of simple “module interconnection languages” (MIL) and subsequently as “configuration languages”, provides generalised support for a wide variety of component and interaction types. Generic (skeleton) architectures provide the means for reusing structures with different constituent components. Dynamic constructs support explicit extension while constraining the potential structures of the system to those expressed as valid. Further, change can be supported at the architectural level, either offline on the design or code, or dynamically on the system itself. System structure (architecture), separately and explicitly described, should be recognised as the unifying framework upon which to hang specification, design, construction and evolution of systems