A Design Pattern Catalog for Applying Large Language Models in the Systems Engineering Lifecycle

ABSTRACT The integration of Large Language Models (LLMs) into the systems engineering lifecycle presents a transformative opportunity to enhance decision‐making, automate documentation, and support complex engineering tasks through intelligent assistance. However, current applications of LLMs in this domain remain fragmented, experimental, and often lack systematic guidance for reuse. This paper presents a structured design pattern catalog for applying LLMs across key phases of the systems engineering lifecycle, including requirements engineering, system architecture, verification and validation, and operations and maintenance. Each design pattern encapsulates a recurring problem, its context, and a proven LLM‐enabled solution, supported by real‐world scenarios and implementation considerations. By formalizing these patterns, we aim to bridge the gap between state‐of‐the‐art language models and established systems engineering practices, enabling practitioners to adopt LLMs more effectively, consistently, and responsibly. The catalog also addresses cross‐cutting concerns such as traceability, human‐in‐the‐loop interaction, and lifecycle integration. A multi‐case study approach, incorporating real‐world industrial applications, validates the identification and practical utility of these patterns, demonstrating their impact on improving systems engineering outcomes.