The importance of reliability in design engineering has significantly grown since the early 1960' s. Competition has been a primary driver in this growth. The three realities of competition today are: world class quality and reliability, cost- effectiveness, and fast time-to-market. Formerly, companies could effectively compete if they could achieve at least two of these features in their products and product development processes, often at the expense of the third. However, customers today, whether military, aerospace, or commercial, have been sensitized to a higher level of expectation and demand products that are highly reliable, yet affordable.