Interacting Threats describe a situation in which one threat is interacting with another, oftentimes resulting in damages that are exponentially greater than if each threat was experienced separately.
The first of these threats are Time Dependent Threats. They’re caused by forces including external corrosion, internal corrosion, and stress corrosion cracking.
The second of these threats are Time-Independent Threats. These are threats caused by nature (i.e., earthquakes) or by people (i.e., construction vehicles hitting your pipeline, vandalism, or letting unknown anomalies progress to the point of catastrophic failure).
The third and final of these threats are called Stable Threats. These threats – for the most part – are associated with the construction and/or maintenance of the pipeline itself. Things like defective pipe seams or manufacturing defects are included in this category of threats.