Formalization and Correctness of the PALS Architectural Pattern for Distributed Real-Time Systems

Many Distributed Real-Time Systems (DRTS), such as integrated modular avionics systems and distributed control systems in motor vehicles, are made up of a collection of components communicating asynchronously among themselves and with their environment that must change their state and respond to environment inputs within hard real-time bounds. Such systems are often safety-critical and need to be certi???ed; but their certi???cation is currently very hard due to their distributed nature. The Physically Asynchronous Logically Synchronous (PALS) architectural pattern can greatly reduce the design and veri???cation complexities of achieving virtual synchrony in a DTRS. This work presents a formal speci???cation of PALS as a formal model transformation that maps a synchronous design, together with a set of performance bounds of the underlying infrastructure, to a formal DRTS speci???cation that is semantically equivalent to the synchronous design. This semantic equivalence is proved, showing that the formal veri???cation of temporal logic properties of the DRTS can be reduced to their veri???cation on the much simpler synchronous design. An avionics system case study is used to illustrate the usefulness of PALS for formal verification purposes.unpublishednot peer reviewe

Abstract State Machines 1988-1998: Commented ASM Bibliography

An annotated bibliography of papers which deal with or use Abstract State Machines (ASMs), as of January 1998.Comment: Also maintained as a BibTeX file at http://www.eecs.umich.edu/gasm

Specifying and Analysing SOC Applications with COWS

COWS is a recently defined process calculus for specifying and combining service-oriented applications, while modelling their dynamic behaviour. Since its introduction, a number of methods and tools have been devised to analyse COWS specifications, like e.g. a type system to check confidentiality properties, a logic and a model checker to express and check functional properties of services. In this paper, by means of a case study in the area of automotive systems, we demonstrate that COWS, with some mild linguistic additions, can model all the phases of the life cycle of service-oriented applications, such as publication, discovery, negotiation, orchestration, deployment, reconfiguration and execution. We also provide a flavour of the properties that can be analysed by using the tools mentioned above