Date of Award

Summer 2014

Document Type


Degree Name

Doctor of Philosophy (PhD)


Engineering Management & Systems Engineering

Committee Director

Charles B. Keating

Committee Member

Resit Unal

Committee Member

Adrian Gheorghe

Committee Member

James Pyne


The purpose of this research was to develop and apply a systems-based method for defining System of Systems (SoS) requirements using an inductive research design. Just as traditional Systems Engineering (TSE) includes a requirements definition phase, so too does System of Systems Engineering (SoSE); only with a wider, more over- arching, systemic perspective. TSE addresses the design and development of a single system with generally a very specific functional purpose enabled by any number of subcomponents. SoSE however, addresses the design and development of a large, complex system to meet a wide range of functional purposes enabled by any number of constituent systems, each of which may have its own individually-managed and funded TSE effort in execution.

To date, the body of prescriptive guidance on how to define SoS requirements is extremely limited and nothing exists today that offers a methodological approach capable of being leveraged against real-world SoS problems. As a result, SoSE practitioners are left attempting to apply TSE techniques, methods, and tools to address requirements for the more complex problems of the SoS domain.

This research addressed this gap in the systems body of knowledge by developing a method, grounded in systems principles and theory, that offers practitioners a systemic, flexible method for defining unifying and measurable SoS requirements. This provides element system managers and engineers a SoS focus to their efforts while still maximizing their autonomy to achieve system-level requirements. A rigorous mixed-method research methodology, employing inductive methods with a case application was used to develop and validate the SoS Requirements Definition Method. Two research questions provided the research focus:

• How does the current body of knowledge inform the definition of a system theoretic construct to define SoS requirements?

• What results from the demonstration of the candidate construct for SoS requirements definition?

Using Discoverers ' Induction (Whewell, 1858), coupled with coding techniques from the grounded theory method (Glaser & Strauss, 1967), a systems-based method for defining SoS requirements was constructed and applied to a real-world SoS requirements definition case. The structured systemic method advances the SoSE field and shows significant promise for further development to support SoSE practitioners in the area of SoS requirements engineering.