Developing Compelling Safety Cases

2025-02-02

AI Summary

Existing safety case methodologies suffer from fragmentation, temporal lag, and an overemphasis on documentation at the expense of practical integration, thereby failing to adequately support safety-critical decision-making across the system lifecycle. This paper proposes a risk-centered, embedded-evolutionary safety argumentation approach that transcends the traditional “post-hoc verification” paradigm by dynamically integrating safety reasoning into system decision-making flows and engineering cognitive processes. The method synergistically combines Goal Structuring Notation (GSN), systems thinking, quantitative risk analysis, and human-factor reflection mechanisms, with explicit emphasis on proactive unsafe scenario identification and closed-loop safety control. Evaluated on an intravenous infusion pump case study, the approach demonstrates substantial improvements in foresight, operational feasibility, and practical guidance—establishing a novel safety assurance paradigm for high-assurance systems that bridges theoretical rigor with engineering deployability.

Technology Category

• Knowledge Representation and Reasoning: Argumentation
• Reasoning under Uncertainty: Applications
• Cognitive Modeling & Cognitive Systems: Conceptual Inference and Reasoning

Application Category

• Security and Privacy: Large-scale security measurements
• Systems and Infrastructure for Web, Mobile and WoT: Experiences and lessons learnt from Web-based algorithms and system deployments
• User Modeling, Personalization and Recommendation: Attacks and countermeasures in recommendation systems

Abstract

This paper describes a method for creating compelling safety cases. The method seeks to help improve safety case practice in order to address the weaknesses identified in current practice, in particular confirmation bias, after-the-fact assurance and safety cases as a paperwork exercise. Rather than creating new notations and tools to address these issues, we contend that it is improvements in the safety case process that will make the most significant improvement to safety case practice. Our method builds upon established approaches and best practice to create an approach that will ensure safety cases are risk-focused, seek to identify ways in which the system may not be safe (rather than just assuming it is), drive safe design and operation of the system (influencing the system itself rather than just documenting what's there), are used to support decisions made throughout the life of the system, including system operation and change, and encourage developers and operators to think about and understand why their system is safe (and when it isn't). A simple example of an infusion pump system is used to illustrate how the new method is applied in practice.

Problem

• System Safety
• Proactive Assessment
• Comprehensive Methodology

Innovation

• Workflow Optimization
• Risk Management
• System Safety