Directly correlating lifetime to coating composition by using standardized, artificial exposures, or even natural exposure, is well-known to be very difficult. Understanding the chemistry and mechanisms of degradation (“bottom-up”) is very valuable for understanding how to improve product performance, but does not indicate the likely extension to product lifetime. A scheme is presented showing how such material science knowledge may be used to make quantitative estimates of end-use properties. It provides a means to organize our knowledge of degradation processes and environments, and for predicting coating properties based on simple models based on the physics of failure.