To be credible a design must not depend on the

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Unformatted text preview: ition strategies, and risk management Control Gates: Non-Advocate Review Program/Project Approval Review System Requirements Review(s) System Definition Review System-level Preliminary Design Review Lower-level Preliminary Design Reviews Safety review(s) NASA Systems Engineering Handbook The Project Life Cycle for Major NASA Systems A Credible, Feasible Design A feasible system design is one that can be implemented as designed and can then accomplish the system's goals within the constraints imposed by the fiscal and operating environment. To be credible, a design must not depend on the occurrence of unforeseen breakthroughs in the state of the art. While a credible design may assume likely improvements in the state of the art, it is nonetheless riskier than one that does not. Early in Phase B, the effort focuses on allocating functions to particular items of hardware, software, personnel, etc. System functional and performance requirements along with architectures and designs become firm as system trades and subsystem trades iterate back and forth in the effort to seek out more cost-effective designs. (Trade studies should precede—rather than followsystem design decisions. Chamberlain, Fox, and Duquette describe a decentralized process for ensuring that such trades lead efficiently to an optimum system design.) Major products to this point include an accepted "functional" baseline and preliminary "design-to" baseline for the system and its major end items. The effort also produces various engineering and management plans to prepare for managing the project's downstream processes, such as verification and operations, and for implementing engineering specialty programs. Along the way to these products, projects are subjected to a Non-Advocate Review, or NAR. This activity seeks to assess the state of project definition in terms of its clarity of objectives and the thoroughness of technical and management plans, technical documentation, alternatives explored, and trade studies performed. Th...
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This document was uploaded on 02/26/2014 for the course E 515 at University of Louisiana at Lafayette.

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