Evaluation model for products´ expected life based on performance degradation amplitude anlysis

Traditional life evaluation theory established on the basis of mass failure data, the phenomena of little or naught failure put forward challenges for existing life evaluation theory. The performance degradation data provides useful information for products´ life and reliability, and gives feasible way for life evaluation. The limitations of existing stochastic process models for performance degradation are analyzed; a new approach based on performance degradation amplitude is brought forward, the calculation methods based on degradation amplitude analysis are given out. For degradation product with large amplitude size, by way of fitting the reliability of every moments, the performance degradation rule can be got and the products´ life can be forecast; for small amplitude size, the degradation path is selected in accordance to engineering experience and products´ failure mechanism, the products´ expected life and reliability is evaluated based on appropriate distribution model. An example of laser device with performance degradation data is given out to validate the effectiveness of the method.