Layered Dependability Modeling of an Air Traffic Control System

Quality attributes, such as performance and dependability of a software-intensive system are constrained by its software architecture. The combined performance and dependability (called performability) effects of an architecture can be evaluated by constructing a performability model that considers the failure/repair behavior and performance attributes of its components, interactions among the components and the fault tolerant approaches adopted. This paper constructs and analyzes a Dependable Layered Queueing Network (Dependable-LQN) performability model for a largescale Air Traffic Control system. It demonstrates the capability of the appraoch, for evaluating the performability of a large-scale software architecture.