Abstract: The burn-in can be used to reduce warranty costs, particularly for products with an initially high failure rate that are sold under warranty. Because previous studies seldom account for burn-in error factors, this study consider such factors in our model to obtain an optimal burn-in time that corresponds more closely with reality. This study focuses on a burn-in test carried out on SDRAM products for the purpose of obtaining reliability and optimal burn-in time and test costs. This study will analyze and validate the data acquired from a life test to determine the types of distributions. The empirical analysis results of this study show that the lifetime of SDRAM products conforms to a Weibull distribution. If the lifetime of an SDRAM product is estimated under such a distribution, a cumulative failure of about 6799 ppm is acquired when the product is operated for one year under normal conditions which is much higher than goal of 100 ppm; thus for the SDRAM products used in this study, the execution of a burn-in is necessary.