Toward a Safety Argumentation Lifecycle for Automated Vehicles: Promoting Communication and Interdependency with System Lifecycle Processes

Abstract: Despite the growing number of automated vehicles on public roads, operating such systems in open contexts will inevitably involve incidents. This results from an inherent risk in road traffic, which arises from multiple sources of complexity and can never be fully eliminated. One central challenge lies in developing a defensible case that the residual risk has been reduced to a reasonable level. While a safety argumentation is a common means to represent this case, there is a need to guide its creation and maintenance by adequate processes. In this paper, we derive requirements for a safety argumentation lifecycle based on examining the current state of the art. In particular, the requirement-driven process design accounts for both identified limitations of current process specifications and implicit knowledge contained in related work. Subsequently, we reflect on interdependencies between the resulting safety argumentation lifecycle and the system lifecycle. Moreover, we discuss a gap in literature regarding transparent ex ante risk communication. Correspondingly, we introduce the concept of representation-supported communication that is based on deriving representations from the argumentation with respect to target stakeholders and communication purposes. Finally, we demonstrate how this approach can be integrated into the system lifecycle to facilitate stakeholder communication.