Today's manufacturers need to develop newer, higher technology products in record time while improving productivity, reliability, and quality. This requires improved accelerated test (AT) methods that can usefully predict service life. For example, automobile manufacturers would like to develop a 3-month test to predict 5 or 10-year field reliability of a coating system. Such estimation/ prediction from ATs involves extrapolation. Seriously inadequate predictions will result unless adequate models and methods are used. This paper describes a general framework within which one can use laboratory test results to predict product field service life performance of certain products in a highly-variable environment.