As per MIL-STD-883E, Method 1005.8, the steady-state life (SS-Life) test is performed for the purpose of demonstrating the quality or reliability of devices subjected to the specified conditions over an extended time period. Life tests conducted within rated operating conditions should be conducted for a sufficiently long test period to assure that results are not characteristic of early failures or “infant mortality,” and periodic observations of results should be made prior to the end of the life test to provide an indication of any significant variation of failure rate with time. Valid results at shorter intervals or at lower stresses require accelerated test conditions or a sufficiently large sample size to provide a reasonable probability of detection of failures in the sample corresponding to the distribution of potential failures in the lot(s) from which the sample was drawn. See the standard documentation for more information on test requirements, conditions, and procedures related to your application.
