Found an interesting blog about the use of scenarios in training.
The models are a vital ingredient of both planning and training. In an emergency plan the reference scenarios can be taken from significant events that have occurred in the past, which must be updated to take account of modern conditions. The scenario can be elaborated in terms of hazard, vulnerability, impact and emergency response. A systems methodology should be used for this (see Figure) and the conditions tailored to a variety of situations, for example with respect to disasters that strike at night or during the day, the outcomes of which are, of course, related to aggregate patterns of human behaviour. As the essence of emergency planning is to anticipate pressing needs in order to supply them effectively at the critical moment, a well-constructed set of crisis or disaster scenarios is an essential aid. Coupled with an audit of emergency resources (vehicles, equipment, supplies, manpower, procedures and protocols) the scenario can help identify potential shortages and deficiencies so that these can be corrected before the next disaster strikes.
You can read the full blog at
http://emergency-planning.blogspot.com/2008/05/use-of-scenarios-for-emergency-training.html
I think all too often we get caught up doing hands on training when in fact table top and discussion exercises can be just as good and challenging. The other big advantage is the far cheaper cost to develop and run.