South-East European Research Centre (SEERC)

The presented work proposes a formal model of a generic scheme which can be used both as a fault-tolerance technique and as a mechanism for displaying graceful degradation in real-time critical systems. In order to deal with the complex forms of interaction that typically arise between the components of such systems, the proposed scheme is based on the concept of Coordinated Atomic Actions – a software engineering concept for structuring complex concurrent activities and supporting cooperative error recovery between multiple interacting processes. The scheme is expressed in the process algebra timed CSP. The presentation will also discuss how the proposed scheme can form the basis of a formal model of a dynamic authorization system in cloud computing.