Reliability prediction of distributed embedded fault-tolerant systems

A new reliability model is introduced for selecting the best software fault-tolerant (FT) design. This model uses a task graph technique that allows different candidate FT configurations to be analyzed based on the structure and organization of different distributed embedded systems. Reliability prediction with this approach can be useful for addressing system dependability issues (i.e., fault detection/recovery processes and steady-state availability) in addition to ascertaining fault coverage (i.e., the likelihood of missing and/or false faults). The results of analyzing three different Simplified Unmanned Vehicle System (SUVS) FT configurations are presented. This work is described within the framework of the Conservative and Do-best FT design policies and fits consistent with a software development model for real-time control systems that was introduced in earlier work by the authors.