Systems Engineering Approach to DfR

Reliability engineering predominantly approaches product development by separating a system into individual components and working bottoms-up, emphasizing hardware/component reliability. As systems become more complex and interconnected, especially with increasing software integration, these methods fail to capture interdependencies and integration points critical to system reliability. A Design for Reliability (DfR) framework solely focused on hardware neglects the intricate dependencies and risks arising from interactions across components.
A systems engineering approach to reliability emphasizes the entirety of the system, ensuring a comprehensive understanding of how different components—hardware, firmware, and software—function together. By examining the system holistically, this approach uncovers hidden vulnerabilities such as cross-system dependencies, cascading failures, and integration point weaknesses that compartmentalized methods overlook. In conventional reliability models, failures are often treated differently across hardware, software, and firmware without recognizing the critical importance of their interactions. This lack of unified analysis frequently results in missed failure modes caused by combining unique parts that do not arise in component-level assessments. Moreover, by focusing only on individual components, organizations may fail to analyze how these components contribute to the overall system function and whether they meet the customer's operational needs. A systems approach ensures that the customer-facing outputs and functional requirements are prioritized so the end product performs reliably under real-world conditions.
This paper explores case studies in critical and emerging industries, such as aerospace, automotive, and internet-of-things (IoT), to highlight the limitations of current reliability practices. It proposes a systems-oriented DfR methodology that shifts focus from isolated hardware approaches to one that accounts for system interdependencies and integration points. This framework enhances system-wide reliability by incorporating hardware and software alongside modeling, simulation, and cross-disciplinary collaboration, ensuring resilience and addressing customer needs in increasingly complex technological environments.

Keywords: Design for Reliability (DfR), Systems engineering, Reliability, Product development.