Step-stress ADT data estimation based on time series method

For long lifetime and high reliability products, it is difficult to obtain failure time data in a short time period. Hence, Accelerated Degradation Testing (ADT) is presented to deal with the cases that few or no failure time data could be obtained but degradation data of the primary parameter of the product are available. Step-Stress ADT (SSADT) is commonly used for the advantage that it needs only a few test samples to conduct a life test. For reliability and lifetime evaluation in SSADT, previous works use deterministic functions to represent the product performance degradation process. However, it does not represent performance degradation information adequately. It is necessary to add stochastic information description to performance degradation process. Time series analysis can represent stochastic information. During the last two decades, considerable research has been carried out in time series analysis. However, only few papers have studied the degradation data analyze method based on time series method. Moreover, SSADT data analysis based on time series method has not been reported in literature at present.