To manage the complex task of estimating Resistance in a pipeline system, especially the effects of damages and weaknesses, the Effective Wall Thickness concept is recommended. This modeling convenience is based on an understanding of the often-complex calculations that allow detailed estimation of strength of pipeline components under varying loads, forces, and stresses. While it is beyond the scope of this site to fully represent all such calculations, a few commonly used tools are offered here.
Fatigue cycle counting
B31G derivative