For a real facility there may be multiple different pathways that must be examined to ensure that they are adequately protected.  It is, therefore, necessary to analyze multiple pathways at once rather than look at each path individually. This is accomplished using an Adversary Sequence Diagram (ASD). The ASD represents all of the potential pathways that an adversary could take, as well as the security elements along each path.

The Adversary Sequence Diagram is created in three steps. The first is to graphically convert physical areas of the facility. For our simple facility shown in Figure 1, the first step in making the ASD is shown in Figure 2.

Figure 1. Simple Facility

Figure 2. Physical Areas of the Facility in ASD Form