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FLEXIBILITY IN DESIGN - Title Page - MIT

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de Neufville + Scholtes D R A F T September 30, 2009difficulty is that this analysis of the sensitivity of a fixed design to alternate scenarios leaves out acrucial reality: the owners and operators of a project will alter the design in line with new realities.They may cut their losses by exiting from a project. They may increase their profits by takingadvantage of new opportunities. They will in any case actively respond to new circumstancesrather than submitting to them passively, as standard evaluation procedures assume. 1People design projects based on a limited set of assumptions and then think aboutuncertainties. They do not design with the uncertainties in mind. As the examples in Box 1.2indicate, system designers do not generally explore how changes in the specifications and marketfactors would change the design itself. In short, our usual design and evaluation procedures focuson an unrealistically narrow description of the possibilities.Box 1.2 about hereA great mismatch thus exists between what actually happens to a project over itsexistence, as the system owners attempt to maximize the value extracted from the project, andour standard ways of valuing and choosing between alternative designs. The reality is that futurebenefits and costs are uncertain, that future adaptation to evolving circumstances iscommonplace, and that designers face a broad range of possible circumstances. Yet thestandard valuation procedures assume that designers can design adequately around a singleconcept of the future benefits and costs – and that users will not deviate from a plan.This mismatch matters. In general, a great difference exists between the valueassociated with the reality of many possible futures, and the value calculated on the assumptionof a single future. This gap exists because equal variations up or down in the imagined futures donot translate into equal variations in values. All the possible futures do not happily average out tothe most likely cash flow. To assume that the average cash flow generates an average value of aproject is to make a fundamental mistake: to be a victim of the “flaw of averages” (see Box 1.3and Appendix A). Designers absolutely need to deal with the broad range of possible futures.Box 1.3 about hereFlexibility in design adds valueOnce we recognize that the future is uncertain, the intelligent thing to do is to prepare for thevarious possibilities. For example, if there is a chance of rain when we go out, the commonsenseapproach is not to ignore this eventuality, but to prepare for it in some way, such as by bringingalong an umbrella. “Be prepared” is a long-standing motto that applies not only to our personallife, but also to our professional life.As both theory and many case studies demonstrate, creating designs that are “prepared”for future possibilities can add great value to a project. Flexible designs enable the owners, themanagers or the operators to adjust the design to new circumstances. When the future turns outto be unfavorable, this can permit them to avoid bad consequences. When the future offers newPart 1: Chapters 1 to 3 <strong>Page</strong> 8 of 69

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