This research explores the relationships between models used to refine the system design, to assess the real-time behavior of the system, and to assess the fault tolerance. these relationships are being combined to develop tools for system- level modeling with dependability analysis of the design. The approach builds on two recently developed tools, ADEPT (Advanced Design Environment Prototype Tool) and DREDD (Dependability and Risk Evaluation using Decision Diagrams). Advanced techniques for dependability analysis of embedded computer systems are being put into the ADEPT design environment. There, a dynamic fault tree model is automatically generated from the ADEPT system design model. The fault tree models uses a combination of Markov techniques, combinatorial approaches and binary decision diagrams. It can model permanent and transient hardware faults, unrelated and related software, automatic recovery and reconfiguration management, sequence dependencies and other dynamic behavior.
