Model for fault tolerance and policy from RM-ODP expressed in UML/OCL

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).