Error Allocation in Complex Systems Design

A fidelity trade environment was conceived, formulated, developed, and demonstrated. This development relied on the advancement of enabling techniques including error propagation, metamodeling, and information management. These techniques were integrated with an existing commercial systems design framework and an intuitive graphical interface to create a fidelity trade environment. A sensitivity approach to the propagation of error through complex systems was developed. This approach relied on the system sensitivity matrix to model the behavior of a complex system as a whole. In verification tests, the sensitivity approach provided approximate results substantially similar to a Monte Carlo approach that was many orders of magnitude more expensive. The rapid sensitivity approach to modeling error propagation enabled the responsive analysis required for an interactive environment. In a case study, a notional transport aircraft was modeled in the fidelity trade environment. The system was decomposed and the fidelity trade environment was used to integrate the system. Then, a scenario was described where a decision maker used the fidelity trade environment at the beginning of a complex systems design problem. Using the environment, the designer was able to make design decisions while considering error and he was able to make decisions regarding required tool fidelity as the design problem continues. These decisions could not be made in a quantitative manner before the fidelity trade environment was developed. The need for a new complex systems design technique was identified. A fidelity trade environment was conceived, establishing the need for advancement of three enabling techniques: error propagation, metamodeling, and information management. All of these techniques were integrated with an existing systems design architecture and an intuitive graphical interface, thereby creating the fidelity trade environment. This environment was applied to a representative complex system, thereby demonstrating its effectiveness in providing a new capability to the designer.