Rule out risk.

Typically in structural design, foreseeable loads are assumed in a dimensioning exercise, and loads or material properties can be introduced with some substantial safety factor to increase confidence in the structure’s load bearing capacity. Structures can, however, be exposed to largely unforeseeable events such as intense environmental phenomena, accidents, malicious acts, and planning or execution errors - let alone degradation with time. This calls for a different, more suitable way of engineering thinking.