The competitiveness of the modern business environment creates a need for shortening the development time while assuring high product reliability. In addition, recent technological advancements in sensor technology and data acquisition have made it possible to continuously monitor the health status or performance of a product during testing. Using such condition monitoring data, the designer can model the degradation process of this product and provides an informative and accurate tool for failure analysis and reliability estimation. Recently, much attention has been focused on developing new reliability growth methods in hopes of speeding up product development in a cost-effective way. To this end, accelerated testing can be conducted in a reliability growth program. One way to take advantage of both accelerated testing and degradation analysis for reliability growth is to conduct accelerated degradation testing (ADT).