A component-based approach to reliability analysis of distributed systems

This paper proposes a reliability analysis technique for distributed software systems. The technique is based on scenarios that are modeled as sequence diagrams. Using scenarios, we construct component-dependency graphs (CDG). CDGs have been introduced for reliability analysis of component-based systems. They are extended to serve the complex nature of distributed systems by applying nesting and hierarchy. CDGs include component and link reliabilities, which are treated as first class elements of the model. Based on CDGs, we present an algorithm to analyze the sensitivity of system reliability to reliabilities of its components, subsystems, and links. The proposed analysis technique is useful in identifying critical components and critical component links. An example based on medical informatics standard is presented to illustrate our methodology