Efficient Sensitivity Analysis of Reliability in Embedded Software

The reliability of software architectures is an important quality attribute in safety-critical systems. Researchers have developed a number of models that can estimate the reliability of software systems at design time. These models use matrix operations of considerable complexity. During the design process of an embedded system as used by the automotive industry, the reliability of a system has to be evaluated after each change. Safety-critical systems are often subjected to sensitivity analysis, where a single parameter is changed numerous times, with a subsequent re-evaluation of the system's reliability. In this paper, we introduce an efficient sensitivity analysis, which computes the change in reliability of the part of the system architecture which was affected by a change. Results from experiments based on a real case-study from the automotive industry indicate a significant improvement in time of the proposed approach compared to traditional sensitivity analysis methods.