where the high cost of changing a light bulb would provide enough incentive to use the more durable energy-efficient light bulbs. The general technology environment is important because relevant applications require integration of several technologies into a system. The availability of the other (enabling) technologies changes over time as well. Often, new and initially superior technologies will be outpaced by continued progress of existing ones. Other technologies can emerge, often for other markets, and make an existing technology suddenly obsolete or nonviable. Societal trends and the political environment are important, especially for human performance modification (HPM) technologies. The effect of the political environment on the development of controversial fields such as stem-cell research or nuclear energy technologies can be drastic and should not be underestimated.
Clearly, the longer it takes to develop a new technology, the less certain the likelihood of success is. One way to assess the time horizon and the technology potential is to look at the “product” lifetime and effect once the technology has been developed (NRC, 1992). Evidently, the time horizon for technology development depends on the product lifetime: a product with a longer lifetime can afford a longer time for development.
Generally, it can be useful to distinguish between two development approaches, and this can help in understanding both the potential and the required development time of a particular technology. As depicted in Figure D-3, one might want to distinguish between a “forward-based” and a “reverse-based” approach. A forward-based approach is typically based on a core technology or research and is exploratory. Basic research has to be carried out to investigate fundamentals of the science that underlies a technology before it can be developed and brought to market. In this scenario, market and products are often being developed after the core technology has been proved and is well under way to being developed. In contrast, a reverse approach is more opportunistic: one looks first at the application and the market opportunity and then finds often-existing technologies, which might need only to be assembled or integrated into a working system.
FIGURE D-3 Technology development approaches.
The relevance of that rather simplistic categorization is that the time horizon for forward-dominated approaches can be different from that for reverse-dominated approaches. Although most technology development is a combination of both approaches and changes over time, particularly as the technology matures, the time horizon in a forward-dominated approach can easily exceed 20 years. Such cases often involve high-risk projects that have unpredictable but potentially game-changing outcomes.
An example of a more forward-dominated approach is the development of near-field technologies for thermally assisted recording in magnetic hard disk drives. This technology allows boosting storage capacity by locally heating the magnetic media and thereby easing the recording process. The technology has been under development for more than 15 years and is