Stochastic Approach in Single Path Analysis of Adversary's Intrusion Strategies in Physical Protection System (PPS) Effectiveness Evaluation

The Estimate of Adversary Sequence Interruption (EASI) model is a single path analysis model to calculate the Probability of Interruption (PI) of a Physical Protection System (PPS) in a facility. However, the PI value from the EASI model does not have uncertainty value which is important to represent the confidence level of the PPS’s performance. Monte Carlo technique, as a stochastic approach, can be used to model the distribution of Probability of Detection (PD) value of the PPS’s element in the EASI model. The adversary may penetrate the facility using different strategies, for example: (1) rushing strategy in which the adversary chooses the fastest way to complete the mission, (2) covert strategy in which the adversary avoids being detected to complete the mission, (3) Most Vulnerable Path (MVP) strategy in which the adversary combines the rushing and covert strategy with respect to the Critical Detection Point (CDP) of the facility to complete the mission. Through a numerous number of single path simulations by also sampling from the PD value of protection elements in the path, this method produces a distribution of PI instead of a single value. Single path analysis of various adversary’s intrusion strategies with this new stochastic approach gives a better insight on the effectiveness of the PPS.