Only a minority of ideas will survive tests and pilots. Even promising ones may simply not be sufficiently effective, or sufficiently cost effective. When an idea or cluster of ideas is new, there are likely to be many competing alternatives. Usually just a few of these survive. Think for example of the bicycle or car, each of which took an extraordinary variety of forms in their first decades (from penny farthings to three-wheelers) before a handful of variants became dominant.
Public feedback may be key, but evaluation methods also have a vital role to play since there is always an element of judgement in determining what counts as success or failure. But the ability to judge innovations, and screen out a high proportion, is critical to the success of an innovation system. Trying to keep too many ideas alive may starve the best ideas of the resources they need to be sustained.
For those that do pass through a period of successful prototyping and testing, launching a service or product on a sustainable basis involves the development of an economic model that will secure its financial future. Often that requires changes to the idea itself: streamlining it; simplifying it; turning into more modular elements so that it can work even without the enthusiasm of pioneers.
In this section, we survey a wide range of assessment tools since similar judgements need to be made as to whether an idea should be sustained or scaled.
(See Robin Murray, Julie Caulier-Grice and Geoff Mulgan, Social Venturing, London: NESTA, 2009.)