Building multiple-viewpoint assurance cases using assumption/guarantee contracts

Abstract

Assurance cases in form of structured arguments are often required by standards to show that a system is acceptable for its intended purpose with respect to a particular assurance viewpoint such as safety or security. The goal of such a case is to present an argument that connects the requirements of a particular viewpoint with the supporting evidence. Building a set of assurance cases for the different viewpoints can be time-consuming and costly. Means are needed to automate and reuse the assurance case artefacts between the assurance cases for the different viewpoints. In this paper we present how assumption/guarantee contracts can be used to facilitate reuse of assurance case artefacts by building multiple-viewpoint assurance cases from the contracts. More specifically, we build upon the previous work on argument-fragment generation from such contracts to allow for generating viewpoint specific argument-fragments. We illustrate the approach on a motivating case.