Systems Theory and a Drive Towards Model-based Safety Analysis

We propose that systems engineering principles taken from multidisciplinary engineering, from model-based design and systems engineering, and from new, emerging methods for safety analysis of complex, coupled systems can be applied to extend the methods of system safety assurance into a so-called field of "Model-based Safety Analysis". The safety analysis methods are based on a model of accident causality that is grounded in systems theory and frames safety as a control problem rather than just a reliability problem. This perspective can capture behaviors that are prevalent in complex, human-and software-intensive systems, and the paper includes a few brief examples to demonstrate the approach. This model-based safety analysis supplements existing model-based systems engineering activities, as well as other safety-related activities and can be applied early in concept development when design details or system specifications are not yet available-it provides a formal means for reasoning about immature system design concepts.