Life evaluation methods based on laboratory and field degradation data

Because of the field degradation data in the life evaluation of products, the method of carrying out accelerated degradation test to obtain data for the supplement of field degradation data has been widely used. In the current design of accelerated degradation test (ADT), the main issue is how to fully simulate the field working stress in laboratory in account of the limitation on hardware devices and financial factors. This will give rise to the evident deviation between predicted performance and field data, which may also lead to the waste of manpower, material and financial resources. Therefore, a life evaluation method which took the laboratory and field degradation data into consideration was proposed. In this method, both laboratory and field degradation data were collected and analyzed; the Bayesian statistical methodology was applied for the estimation and correction of the accelerated life model and the life distribution of products with the ADT data and field degradation data to get a more accurate life evaluation. At the end of the article, an example is given to illuminate the application and computational process of the method, as well as the analysis of the accuracy of evaluation method.