Developing Effectiveness Measures for System Analysis Tools in Hypersonic Vehicle Design

Throughout the design process, systems engineers use analysis tools to characterize the composition, development, and behavior of complex engineered systems. As such, designers must ensure that these tools generate accurate results for the systems they’re designed to analyze. One such suite of tools is the Analytic Workbench (AWB), a framework couched in a model-based systems engineering (MBSE) environment which provides methods for integrating constituent systems into a system-of-systems (SoS) or a complex engineered system, while taking into account the capabilities and requirements of the constituent systems, and the interdependencies between them. Hypersonic vehicles present a number of design challenges that result in a narrow performance envelope and a high degree of interdependence between subsystems, and so the AWB provides an appropriate tool set for characterizing the conceptual design of this class of system. The purpose of this thesis is to generate effectiveness metrics for the tools within the AWB — specifically Robust Portfolio Optimization (RPO) and System Developmental Dependency Analysis (SDDA) — in the context of a hypersonic vehicle design problem. In particular, this thesis focuses on verification and validation metrics, and applies these metrics to several demonstration cases, in which the outputs of RPO and SDDA analyses of a hypersonic vehicle model consisting of top-level subsystems are compared with a hypothetical physical vehicle. This thesis examines several candidate effectiveness metrics, and then applies the ones that satisfy the requirements for RPO and SDDA verification and validation to the appropriate demonstration cases. The AWB outputs for the vehicle models in these demonstration cases deviate slightly from the corresponding quantities for the hypothetical physical vehicles, and the effectiveness metrics decrease in value the greater these deviations are. Subsequent explorations of these metrics could apply these effectiveness to other types of design problems, including analyses involving lower-level subsystems of hypersonic vehicles.