The Science and Technology of Counterterrorism

Appendix A

Linearity, Nonlinearity, and Parametric Scaling

Risk can sometimes be evaluated more precisely because of a relationship to physical quantities that obey natural laws. These physical quantities are themselves a function of parameters like distance and time. One can then examine the effect of these quantities on risk using a range of parameter values dictated by scenario-specific conditions.

For example, if one hopes to evaluate the vulnerability of a facility to vehicle-borne explosives, one must do so for various payloads and standoff distances in order to develop an effective mitigation strategy. It is unlikely an adversary will advertise the plan of attack, and therefore a distribution of possible attack scenarios is required.

Because ...