Having gotten to the point of defining environments, materials and modes, the next step is to integrate these steps to determine whether there is a concern about performance. In this step, for a given material, the parameters of the modes and local environments on the surface are compared. In a graphical sense the environments and modes can be superimposed providing they are organized in the same coordinates, such as pH and potential; and possible intersections can be determined directly by overlap.

The question to be considered here is whether the variables that describe environments on the surface are, at least to some extent, coincident with those that describe the various possible modes of failure. If such coincidence occurs, then the materials, designs or environments may need to be modified before any further steps are taken.

Lifetime Prediction, Roger W. Staehle, Adjunct Professor, Department of Chemical Engineering and Materials Science, University of Minnesota, Staehle Consulting Co.