A Framework for Modeling Dependable Real-Time Distributed Systems

Abstract A systematic way to introduce fault-tolerant and time-dependent properties into a complex software system is presented. The approach is based on an extended Petri Net model, called the G-Net, enhanced with the deterministic timing scheme. An object-based approach, enhanced with exception handling and time-out mechanism, is used to introduce the fault tolerance properties. The basic idea is to avoid the timing error propagation from a faulty object to an object that interacts with it via a time-out mechanism, and also to allow an object to treat a timing error by raising an exception and triggering some corrective actions.