Reuse of Formal Specifications in Computer-Based Systems Design

Formal specification, reuse, finite-state automaton, timed automaton, case-based reasoning.

This paper deals with reuse of architectural and behavioral specifications of computer-based systems employing finite-state and timed automata. The contribution proposes not only how to represent a system formal specification as an application pattern structure of specification fragments, but also how to measure similarity of formal specifications for retrieval with case-based reasoning support. To demonstrate formal specification reuse, two case studies based on real design projects are employed: (1) petrol pumping station dispenser controller and (2) multiple lift control system. The paper discusses identification and representation of reusable architectural components and their retrieval, adaptation, and storage with case-based reasoning support. The first part of the paper introduces the concepts of application patterns relating them to the well-known object-oriented design abstractions. Evidently, to reuse an architectural component whose implementation consists both of software and hardware, it means to reuse its formal specification. The second part of the paper provides an insight into case-based reasoning support as applied to formal specification reuse by application patterns built on finite-state and timed automata.