Architecture Modeling and Interface Risk Assessment for Cross-Organizational Development of Safety-Critical System

This study proposes a framework to support early-stage design of safety-critical systems across multiple organizations. In such development, adding safety functions to prevent off-nominal states often increases complexity and interface dependencies, which can hinder efficient development. To address this, we build an MBSE-based architecture model that describes dependencies among operations, functions, systems, and organizations. We also introduce complexity metrics to evaluate cross-domain interface risks. A case study on spacecraft rendezvous-and-capture operations illustrates how our method models both nominal and off-nominal scenarios, identifies high-risk interface paths, and supports early architectural decision-making.