Assuring design using Bayesian Networks to support quantifying knowledge and evidence

Abstract

ABSTRACTAssuring the design and maintenance of complex systems is itself a complex undertaking. Claims regarding the suitability of a design for a particular purpose need to be supported by evidence of design accomplishment and process compliance. The Goal Structuring Notation can be used to support argumentation of particular claims, including system safety and system assurance claims. While argument claims need to be supported by evidence, the strength of the evidence supporting a claim is often not systematically considered. Restructuring argument claims as a Bayesian Network supports systematically quantifying the likelihood of the veracity of evidence supporting the claim. Using an Object-based Bayesian Network allows this model to be rapidly expanded to consider multiple systems of systems. The application of this method to a simple Technical Integrity assurance argument is shown. Similarly, the technique can be used to support a safety argument.