Human Factors in the Unified Architecture Framework Applied to Space Situational Awareness

Abstract

Driven by the ever-increasing complexity of human endeavors, the field of systems engineering is in the midst of a revolution of its practices. One well-developed aspect of this revolution is the replacement of document-based systems engineering with transdisciplinary model-based systems engineering in which all technical aspects are brought into the model. Remaining work in this field is the inclusion of all aspects of the enterprise related to the system-of-interest within the model, hence architectural frameworks are expanding downward to include system aspects. The Unified Architecture Framework (UAF) is directly expressible in Systems Modeling Language (SysML), in contrast with its predecessors. The integration of enterprise architecture frameworks with system specific modeling resolves the perennial divide within systems engineering: how to represent humans (e.g. operators) in system engineering products. Whether or not humans are modeled within any system boundary becomes less crucial as engineering disciplines begin to understand that humans are clearly part of the enterprise. If the UAF did nothing but unify the systems engineering community in a common stance on human factors, its value would be hard to overstate.This report presents a case study exploring the design of a Collaborative Command System (CCS) for operators of a Space Situational Awareness (SSA) system. The study utilized MagicDraw’s Cameo System Modeler, as well as its new UAF perspective plug-in. The study evaluated a baseline CCS against the criteria of requirement coverage, human interaction coverage, human capacity coverage, and human to end-user coverage as driven by the UAF. This evaluation revealed that the model met the criteria for requirement coverage as well as the human interaction coverage, but failed to meet both the human capacity coverage and human to end-user coverage in its current form. The UAF therefore offered significant benefit by illustrating insufficiencies in the design as well as suggesting what future design refinements and enhancements should be addressed.