Assurance of System Safety: A Survey of Design and Argument Patterns

TL;DR

This survey reviews safety assurance patterns in safety-critical systems, highlighting research trends, classifications, and gaps, especially regarding how patterns influence safety claims and the integration of security considerations.

Contribution

It provides a comprehensive taxonomy of safety assurance patterns and identifies key research gaps in their impact on safety claims and security integration.

Findings

Lack of research on how patterns improve safety claims

Insufficient analysis of safety pattern decomposition

Limited exploration of security's impact on safety

Abstract

The specification, design, and assurance of safety encompasses various concepts and best practices, subject of reuse in form of patterns. This work summarizes applied research on such concepts and practices with a focus on the last two decades and on the state-of-the-art of patterns in safety-critical system design and assurance argumentation. We investigate several aspects of such patterns, for example, where and when they are applied, their characteristics and purposes, and how they are related. For each aspect, we provide an overview of relevant studies and synthesize a taxonomy of first principles underlying these patterns. Furthermore, we comment on how these studies address known challenges and we discuss suggestions for further research. Our findings disclose a lack of research on how patterns improve system safety claims and, vice versa, on the decomposition of system safety into separated local concerns, and on the impact of security on safety.