AbstractMemory modules used in personal computers were discovered to have a potential reliability defect caused by a fault in the module manufacturing process.In order to assess the eventual impact on personal computer reliability, should it be decided to use these modules, thermal stress testing and subsequent analysis of the results was performed.Several approaches were employed in the calculation of the relevant statistical parameters which would describe the failure pattern; and the validity of each approach was assessed by comparing predicted with actual results. The optimum approach was used in making a projection to normal operating conditions.Finally the analysis was developed to account for the configuration of modules as assembled in the personal computer. This last stage of the analysis allowed the definition of the expected failure pattern of the machine due to defective memory modules.