OpenMDAO is very much an option, though it is geared more for model-based analysis and numerical optimization for highly integrated systems. The primary use cas

OpenMDAO is very much an option, though it is geared more for model-based analysis and numerical optimization for highly integrated systems. The primary use case is to assist in early conceptual design, particularly for vehicles. But basically, it's a Python framework for passing variables, functions, and derivatives of functions around between disparate codes. In practice, the most common systems engineering tools that I've seen are actually excel and powerpoint. Not knocking either of those tools (or the role of systems engineer), but that seems to be the current state of the field.