THE USE OF ISEM IN STUDYING THE IMPACT OF GUARD TACTICS ON FACILITY SAFEGUARDS SYSTEM EFFECTIVENESS

The Insider Safeguards Effectiveness Model (ISEM) is a stochastic, discrete event, Monte-Carlo Simulation Model used to assess the effectiveness of physical protection systems for facilities which store, process, or use SNM. ISEM simulates the interaction of a group of insiders (adversaries who are guards or other employees having authorized access to the facility) with the facility's safeguards system. The facility is described in terms of a set of areas, portals, and barriers. These facility entities are assigned attributes such as number of employees, number and type of sensors, detection probabilities, and delay times. The sensor control and alarm locations are correlated with the authorized access areas of the insider (s) and, if the insider has the appropriate access, the probability of an insider successfully defeating a sensor control or alarm is computed based upon the surveillance subsystems and the insider's attributes. Following an alarm and an assessment, actions are initiated by the safeguards system. These actions typically involve dispatching guards to specific locations within the facility. Since the specific guard responses must be predetermined, a safeguards system should be evolved from a consideration of a wide spectrum of feasible adversary strategies. The sensitivity of safeguards system effectiveness to a variety of guard tactics is explored in this paper. The evolution of comprehensive guard tactics for protecting a hypothetical facility is demonstrated. Attention is focused on the potential threat posed by insiders and the necessity of well conceived guard tactics in dealing with this threat.