The objectives of a vulnerability analysis of an industrial system may comprise: (1) To identify potential threats to the system (2) To verify that the vulnerability of the system is acceptable (3) To verify that the system's security actions and installations, and safety functions are adequate (4) To evaluate the cost-effectiveness of a proposed action to improve the vulnerability (5) To aid in establishing an emergency preparedness plan (6) As a design tool-to design a robust system. In a vulnerability analysis we work with open system models, where risk factors both inside and outside the physical boundaries of the system are taken into account. A vulnerability analysis and a risk analysis of the same company will therefore produce quite different sets of accidental events. A traditional risk analysis is mainly limited to accidental events taking place within the physical boundaries of the system, and the threats studied are often limited to technological hazards within these boundaries. The actions to mitigate, restore and restart the activities after an accident are normally not part of a risk analysis. A vulnerability analysis focuses on the whole disruption period until a new stable situation is obtained. The focal point of a vulnerability analysis is the (business) survivability of the system. (Einarsson and Raussand 1998)