A Framework for Machine-Assisted Software Architecture Validation

Abstract

In this thesis we propose a formal framework for specifying and validating properties of software system architectures. The framework is founded on a model of software architecture description languages (ADLs) and uses a theorem-proving based approach to formally and mechanically establish properties of architectures. Our approach allows models defined using existing ADLs to be validated against properties that may not be expressible using the original notation and tool-set. The central component of the framework is a conceptual model of architecture description languages. The model formalizes a salient, shared set of design categories, relationships and constraints that are fundamental to these notations. An advantage of an approach based on a conceptual model is that it provides a uniform view of design information across a selection of languages. This allows us to construct alternate formal representations of design information specified using existing ADLs. These representations can then be mechanically validated to ensure they meet their specific formal requirements. After defining the model we embed it in the logic of the PVS theorem-proving environment and illustrate its utility with a case study. We first demonstrate how the elements of a design are specified using the model, and then show how this representation is validated using machine-assisted proof. Our approach allows the correctness of a design to be established against a wide range of properties. We illustrate with structural properties, behavioural properties, relationships between the structural and behavioural specification, and dynamic, or evolving aspects of a system's topology.