Many high-performance units made today can have extremely large reliabilities when they are operating as intended. For example, through advances in engineering science, a measurement such as time to failure for an electronic device could be quite large. For these situations, calculating the reliability is still of interest to the manufacturer and to the consumer, but a long period of time may be necessary to obtain sufficient data to estimate reliability. This is a major issue, since it is often the case with electronic components that the length of time required for the test may actually eclipse the "useful lifetime" of the component. In addition, performing a test over a long time period (possibly many years) could be very costly. One solution to this issue of obtaining meaningful life test data in a timely fashion is to perform an Accelerated Life Test (ALT). ALT consists of a variety of test methods for shortening the life of test items or hastening the degradation of their performance. The aim of such testing is to obtain data quickly, which when properly modeled and analyzed, yields desired information on product life or performance under usual conditions.