The history of reliability as we know it now goes back to the 1950s, when electronics played a major role for the first time [1,2]. Now, 70 decades later, the electronic industry is facing a continuous increase of early and wear-out failures with accompanying consequences. Figure 13.1 depicts the struggle for the different high-tech industries, ranging from harsh environment suitability to long lifetime and warranty coverage. Nowadays, products with high failure rates are logged on the web leading to bad reputation for a company. In many ways, reliability is part of everyday life and part of consumer expectations. The word reliability is extensively used by the general public and the technical community, as illustrated by the following: there are over 3000 published books whose title or keywords contain the word reliability; the web of science lists some 10,000 technical papers with "reliability" as a keyword (since 1973); and the popular search engine Google lists over 12 million occurrences of "reliability" on the world wide web.Solid state lighting applications are now at the doorstep of massive market entry [3,4]. The penetration will grow most rapidly in the street and roadway and general service submarkets in terms of the percentage of total lumen-hour sales [5][6][7]. Scenarios estimate the expected future adoption of LEDs based on historical data