Abstract :
Fault tolerance (FT) is a topic of major concern in achieving dependable systems, for both real time as well as non real time systems. The paper provides a model of achieving fault tolerance, based on the ISO/ITU Reference Model for Open Distributed Processing (RM-ODP). This reference model provides a system software engineering methodology for fault tolerance, an object based model of fault tolerance, system requirements for achieving fault tolerance in an open manner, modeling constructs and rules to enable a proper system specification of fault tolerance, and business rules in terms of policies to achieve a well formed system specification. All these aspects are discussed at some depth, but the author primarily focuses on how certain behavior can be specified and achieved in an object based system, the constructs of the Unified Modeling Language (UML) and the Object Constraint Language (OCL)
Keywords :
distributed programming; formal specification; object-oriented languages; object-oriented programming; open systems; software fault tolerance; software standards; ISO/ITU Reference Model; Object Constraint Language; Open Distributed Processing; RM-ODP; UML/OCL; Unified Modeling Language; business rules; dependable systems; fault tolerance; modeling constructs; non real time systems; object based model; real time systems; system requirements; system software engineering methodology; system specification; Distributed processing; Environmental management; Fault tolerance; Fault tolerant systems; ISO standards; Real time systems; Security; System software; Systems engineering and theory; Unified modeling language;