Design Life Verification through Accelerated Life Testing

Sarath Jayatilleka

The term ‘life’ in Accelerated Life Testing (ALT) needs to be taken very seriously in designing an ALT. Without a well-defined life, designing an ALT is not possible. Design Life of a new product is a key design input. Design Life of a system is typically derived from the voice of the customer. While customer’s voice dictates design life in calendar times such as in years, the subsystem and component lives are derived (or decomposed) down to functional usage duty cycles (FUDC) of those subsystems and components. Systems Engineering V-Model is used in support of illustration of ‘life requirement’ decomposition from system down to components. Life requirement derivation is a simple process in some cases like a gear wheel of shorthand of a clock while it becomes a challenge in some other cases like an integrated bipolar thyristor of a variable frequency drive. Both simple and complex processes are discussed with examples. The benefits of well-designed ALTs such as verification of reliability requirements, screening of suppliers and design options are discussed with examples in this paper