Before the analysis can start, it must be clear to which threats this organisation may be exposed. For example, the in-company fire service in charge of chemical plant safety will be confronted with different potential disasters than a crisis team controlling the spread of agricultural diseases. The latter is unlikely to be affected by violent destruction of hardware. Consequently, the threats to their telecom services will be very different in nature.
The threats to telecom services and their mechanisms must be described in as much detail as possible. Disaster scenarios describe the threats, their effects and mechanisms, their likelihood, and the required response from the case organisation.
In the Netherlands tornados seldom lead to damage to infrastructures. Typically, the threat of tornados will therefore be excluded from disaster scenarios. Flooding from sea or riverbeds, however, are quite common, and will likely be included.
For some studies intentional human-made events (crime, terrorism) are highly relevant. For other studies it may suffice to focus on accidental events only. The scope of the study need not be limited to technical aspects. When describing a disaster, the effects that it will have on telecom components is the most important part. To better understand the reactions of the general public it may be useful to also include some graphic descriptions of events that could be experienced by citizens, or that could be published in the media. This may facilitate the assessment of social risk factors in the Risk Evaluation stage.
It may be possible to reuse disaster scenarios from previous risk assessments, thus shortening the amount of work needed.