Many companies have an increasing need to analyse, verify, and document the lifetime of their newly developed or existing products. They need methods to find out how long their products will last, so that they know what they can guarantee to their customers and what this guarantee will end up costing. An accelerated lifetime test is a way of fast forwarding time so that we do not have to wait 20 years to find out whether a product can actually last 20 years in the real world.