Measure Confidence of Assurance Cases in Safety-Critical Domains

Abstract

Evaluation of assurance cases typically requires certifiers' domain knowledge and experience, and, as such, most software certification has been conducted manually. Given the advancement in uncertainty theories and software traceability, we envision that these technologies can synergistically be combined and leveraged to offer some degree of automation to improve the certifiers' capability to perform software certification. To this end, we present a novel confidence calculation framework that 1) applies the Dempster-Shafer theory as a mathematical model to calculate the confidence between a parent claim and its children claims; and 2) uses the vector space model to evaluate the confidence for the evidence items using traceability information. A fragment of an assurance case (expressed in the goal-structuring notation – GSN) for the coupled tank system is used to illustrate our new framework.