Output details

Bivariate constant stress degradation model: LED lighting system reliability estimation with two-stage modelling

At the time of the research, LED was a new form of lighting entering mass production and the designs of LED systems needed improvement to extend the life of the bulbs. Joint experimental research on LED systems in the development and testing phase of design helped to identify product parameters (most importantly heat dissipation and voltage) that extended or shortened their life. The experimental results and theoretical modelling resulted in design changes. A new approach using copulas captured complex relationships between the several performance characteristics. The estimated life time distributions are used in maintenance and replacement planning.