UL 4600, the safety standard for autonomous products, mandates the use of Safety Performance Indicators (SPIs) to continuously ensure the validity of safety cases by monitoring and taking action when violations are identified. Despite numerous examples of concrete SPIs available in the standard and companion literature, their contribution rationale for achieving safety is often left implicit. In this paper, we present our initial work towards an argument pattern for the use of SPIs to ensure validity of safety cases throughout the entire lifecycle of the system. Our aim is to make the implicit argument behind using SPIs explicit, and based on this, to analyze the situations that can undermine confidence in the chosen set of SPIs. To maintain the confidence in SPIs' effectiveness, we propose an approach to continuously monitor their expected performance by using meta-SPIs.

翻译：UL 4600作为自动驾驶产品的安全标准，要求采用安全性能指标（SPIs）通过持续监控并在识别违规时采取行动，以确保安全案例的有效性。尽管该标准及其配套文献提供了大量具体SPIs的实例，但其实现安全性的贡献逻辑往往隐含未明。本文提出了我们为构建SPIs使用论证模式的初步工作，旨在确保系统全生命周期内安全案例的有效性。我们的目标在于显式揭示使用SPIs背后的隐含论证，并基于此分析可能削弱对所选SPIs集合信心的潜在情境。为维持对SPIs有效性的信心，我们提出一种通过元SPIs持续监控其预期性能的方法。