A computer-implemented method for use in evaluating at least one threat to a complex system includes identifying one or more physical components of the complex system and modeling the one or more physical components with interactive software multi-agents. The multi-agents are programmed to monitor and control at least one function of the modeled physical components. One or more threats to a target of the complex system are identified. Each threat is defined as a cyber threat or physical threat and the target is defined as a cyber component or physical component. The method includes simulating an attack on the complex system by the identified threat and assessing an impact of the attack on the complex system.