Approaching Safety-Argumentation-by-Design: A Requirement-based Safety Argumentation Life Cycle for Automated Vehicles
This addresses the need for robust safety justification in automated driving to manage liability risks, though it is incremental as it builds on existing design models and process guidance.
The paper tackles the challenge of developing defensible safety arguments for automated vehicles by proposing a safety-argumentation-by-design paradigm, resulting in a dedicated argumentation life cycle with phases like baselining and evolution to co-develop systems and arguments from early stages.
Despite the growing number of automated vehicles on public roads, operating such systems in open contexts inevitably involves incidents. Developing a defensible case that the residual risk is reduced to a reasonable (societally acceptable) level is hence a prerequisite to be prepared for potential liability cases. A "safety argumentation" is a common means to represent this case. In this paper, we contribute to the state of the art in terms of process guidance on argumentation creation and maintenance - aiming to promote a safety-argumentation-by-design paradigm, which mandates co-developing both the system and argumentation from the earliest stages. Initially, we extend a systematic design model for automated driving functions with an argumentation layer to address prevailing misconceptions regarding the development of safety arguments in a process context. Identified limitations of this extension motivate our complementary design of a dedicated argumentation life cycle that serves as an additional process viewpoint. Correspondingly, we define literature- and expert-based process requirements. To illustrate the safety argumentation life cycle that we propose as a result of implementing these consolidated requirements, we demonstrate principles of the introduced process phases (baselining, evolution, continuous maintenance) by an argumentation example on an operational design domain exit response.