Editing Software prototyping (section)

===Evolutionary prototyping===

Evolutionary prototyping (also known as [[breadboard]] prototyping) is quite different from [[Software_prototyping#Throwaway_prototyping|throwaway prototyping]]. The main goal when using evolutionary prototyping is to build a very robust prototype in a structured manner and constantly refine it. The reason for this approach is that the evolutionary prototype, when built, forms the heart of the new system, and the improvements and further requirements will then be built.

When developing a system using evolutionary prototyping, the system is continually refined and rebuilt. 
:"…evolutionary prototyping acknowledges that we do not understand all the requirements and builds only those that are well understood."<ref name=Davis1992p71>Alan M. Davis: Operational Prototyping: A new Development Approach. IEEE Software, September 1992. Page 71.</ref>
This technique allows the development team to add features, or make changes that couldn't be conceived during the requirements and design phase.

:For a system to be useful, it must evolve through use in its intended operational environment. A product is never "done;" it is always maturing as the usage environment changes…we often try to define a system using our most familiar frame of reference—where we are now. We make assumptions about the way business will be conducted and the technology base on which the business will be implemented. A plan is enacted to develop the capability, and, sooner or later, something resembling the envisioned system is delivered.<ref name=SoftwareProductivityConsortium1997p6>Software Productivity Consortium: Evolutionary Rapid Development. SPC document SPC-97057-CMC, version 01.00.04, June 1997. Herndon, Va. Page 6.</ref>

Evolutionary prototypes have an advantage over throwaway prototypes in that they are functional systems. Although they may not have all the features the users have planned, they may be used on an interim basis until the final system is delivered.

:"It is not unusual within a prototyping environment for the user to put an initial prototype to practical use while waiting for a more developed version…The user may decide that a 'flawed' system is better than no system at all."<ref name=Crinnion1991p18/>

In evolutionary prototyping, developers can focus themselves to develop parts of the system that they understand instead of working on developing a whole system.

:To minimize risk, the developer does not implement poorly understood features. The partial system is sent to customer sites. As users work with the system, they detect opportunities for new features and give requests for these features to developers. Developers then take these enhancement requests along with their own and use sound configuration-management practices to change the software-requirements specification, update the design, recode and retest.<ref>Davis. Page 72-73. Citing: E. Bersoff and A. Davis, Impacts of Life Cycle Models of Software Configuration Management. Comm. ACM, Aug. 1991, pp.&nbsp;104–118</ref>