Toward a Harmonized Approach -- Requirement-based Structuring of a Safety Assurance Argumentation for Automated Vehicles

Despite the increasing testing operations of automated vehicles on public roads, media reports on incidents show that safety issues caused by automated driving systems persist to this day. Manufacturers face high development uncertainty when aiming to deploy these systems in an open context. In particular, one challenge is establishing a valid argument at design time that the vehicles will exhibit reasonable residual risk when operating in its intended operational design domain. While there is extensive literature on assurance cases for safety-critical systems in general, the domain of automated driving lacks explicit requirements regarding the creation of safety assurance argumentations for automated vehicles. In this paper, we aim to narrow this gap by elaborating a requirement-based approach. We identify structural requirements for an argumentation based on published literature and supplement these with structural requirements derived from stakeholder concerns. We apply these requirements to obtain a proposal for a generic argumentation structure. The resulting "safety arguments" address the developed product (product argument), the underlying process (process argument) including its conformance/compliance to standards/laws (conformance/compliance argument), as well as an argumentation's context (context argument) and soundness (soundness argument). Finally, we outline argumentation principles in accordance with domain-specific needs and concepts.