Refinement of Information Flow Architectures
This work addresses the problem of system design and verification for researchers and engineers in formal methods or software architecture, but it appears incremental as it builds on existing concepts of refinement and composition.
The paper tackles the problem of refining abstract information flow architectures by presenting a calculus for stepwise refinement, using a mathematical model based on relations between input and output communication histories, and it results in a method for hierarchically composing systems with correctness justified by refinement relations.
A calculus is presented for the stepwise refinement of abstract information flow architectures. We give a mathematical model for information flow components based on relations between input and output communication histories, and describe system architectures using two views: the glass box view is a network of basic components, while the black box view regards the network itself as a component. This allows us to hierarchically compose systems. The calculus consists of basic rules to add or remove components and channels, and to replace components by subnetworks and vice versa. The correctness of the rules is justified by the refinement relation on the black box view of architectures.