Six-Assurance Case Patterns by Strengthening/Weakening Argument

Abstract

Goal structuring notation (GSN) is widely used in safety cases and other methods for assuring reliability. Demonstrating the fulfillment of a claim in the GSN requires that its achievement be interpreted logically and structurally by the reader. This study proposes a typical pattern of interpreting these structural interpretations. Furthermore, the proposed patterns were verified for their application to actual GSN samples, and the applicability of these patterns was validated. In addition, these patterns were compared with the existing use of the so-called multi-legged arguments, and the differences between them were shown. Moreover, some of the proposed patterns show that there is a difference in the degree of certainty in the achievement of the converted claim, which indicates achievement of the claim from which it is derived.