This paper discusses the integration of product, test, diagnostic, and sustainment engineering disciplines using a standards-based digital thread. After reviewing some of the relative strengths and challenges of this approach (as compared to other trends in digital engineering), we present a case study in which a standards-based digital thread is used to flow detailed design data into diagnostic and test engineering activities. This integration not only creates opportunities for seamless automation during product development, but also provides full traceability from engineering databases to the test programs performed on Automatic Test Systems and subsequent test results and diagnostic reasoning. Notably, because all essential model data is stored unambiguously in the thread, the thread itself becomes the authoritative source of truth for a given project or enterprise.

Keywords—digital engineering, digital thread, model-based engineering, diagnostic engineering, test program set development.