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Value-driven design (VDD) is a systems engineering strategy based on microeconomics which enables multidisciplinary design optimization. Value-driven design is being developed by the American Institute of Aeronautics and Astronautics, through a program committee of government, industry and academic representatives.〔(【引用サイトリンク】url= http://www.aiaa.org/content.cfm?pageid=484 )〕 In parallel, the US Defense Advanced Research Projects Agency has promulgated an identical strategy, calling it Value centric design, on the F6 Program. At this point, the terms ''value-driven design'' and ''value centric design'' are interchangeable. The essence of these strategies is that design choices are made to maximize system value rather than to meet performance requirements. This is also similar to the ''value-driven'' approach of ''agile software development'' where a project's stakeholders prioritise their high-level needs (or system features) based on the perceived business value each would deliver. Value-driven design is controversial because performance requirements are a central element of systems engineering. However, value-driven design supporters claim that it can improve the development of large aerospace systems by reducing or eliminating cost overruns which are a major problem, according to independent auditors. ==Concept== Value-driven design creates an environment that enables and encourages design optimization by providing designers with an objective function and eliminating those constraints which have been expressed as performance requirements. The objective function inputs all the important attributes of the system being designed, and outputs a score. The higher the score, the better the design. Describing an early version of what is now called value-driven design, George Hazelrigg said, "The purpose of this framework is to enable the assessment of a value for every design option so that options can be rationally compared and a choice taken." At the whole system level, the objective function which performs this assessment of value is called a "value model." The value model distinguishes value-driven design from Multi-Attribute Utility Theory applied to design. Whereas in Multi-Attribute Utility Theory, an objective function is constructed from stakeholder assessments, value-driven design employs economic analysis to build a value model. The basis for the value model is often an expression of profit for a business, but economic value models have also been developed for other organizations, such as government.〔 To design a system, engineers first take system attributes that would traditionally be assigned performance requirements, like the range and fuel consumption of an aircraft, and build a system value model that uses all these attributes as inputs. Next, the conceptual design is optimized to maximize the output of the value model. Then, when the system is decomposed into components, an objective function for each component is derived from the system value model through a sensitivity analysis.〔 A workshop exercise implementing value-driven design for a global positioning satellite was conducted in 2006, and may serve as an example of the process. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Value-driven design」の詳細全文を読む スポンサード リンク
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