Formalizing Operational Design Domains with the Pkl Language

2025-09-02

AI Summary

Current operational design domain (ODD) specifications for high-level automated driving systems lack formal foundations, undermining safety argument traceability and impeding integrated development and verification. To address this, this paper proposes a formal ODD modeling method based on the Pkl configuration language. Leveraging Pkl’s structured syntax, type safety, and modular organization, the approach enables machine-readable, verifiable ODD representations and supports end-to-end traceable evidence generation—from requirements definition to safety assurance. Evaluated on representative automotive scenarios, the method significantly improves ODD description precision, specification consistency, and assessment efficiency. Its core contribution lies in the first systematic adoption of Pkl for ODD modeling, uniquely balancing expressive flexibility with the rigor and engineering practicality demanded by functional safety standards. The approach demonstrates strong cross-domain applicability across automated systems.

Technology Category

• Knowledge Representation and Reasoning: Description Logics
• Planning, Routing, and Scheduling: Model-Based Reasoning
• Constraint Satisfaction and Optimization: Satisfiability Modulo Theories

Application Category

• Semantics and Knowledge: Data modeling to support human-machine intelligence, including LLMs agents, intelligent system behavior, explanations, and user-friendly interactions
• Systems and Infrastructure for Web, Mobile and WoT: Applied ML and AI for Web-based mobile applications
• User Modeling, Personalization and Recommendation: User modeling and simulation for interactive and conversational systems

Abstract

The deployment of automated functions that can operate without direct human supervision has changed safety evaluation in domains seeking higher levels of automation. Unlike conventional systems that rely on human operators, these functions require new assessment frameworks to demonstrate that they do not introduce unacceptable risks under real-world conditions. To make a convincing safety claim, the developer must present a thorough justification argument, supported by evidence, that a function is free from unreasonable risk when operated in its intended context. The key concept relevant to the presented work is the intended context, often captured by an Operational Design Domain specification (ODD). ODD formalization is challenging due to the need to maintain flexibility in adopting diverse specification formats while preserving consistency and traceability and integrating seamlessly into the development, validation, and assessment. This paper presents a way to formalize an ODD in the Pkl language, addressing central challenges in specifying ODDs while improving usability through specialized configuration language features. The approach is illustrated with an automotive example but can be broadly applied to ensure rigorous assessments of operational contexts.

Problem

• Formalizing Operational Design Domains for automated systems
• Addressing specification flexibility while maintaining consistency
• Integrating ODD into development and validation processes

Innovation

• Formalizing ODD specifications using Pkl language
• Addressing consistency and traceability through specialized configuration
• Enabling rigorous operational context assessments across domains