Selecting Scenarios

An emergency plan is only as good as the scenarios behind it. Generic plans produce generic responses that fit nothing.

Where scenarios come from

• The major accident hazards identified in the risk assessments and bow-ties.
• The emergency conditions in the environmental aspects register — spills, firewater run-off, uncontrolled discharge.
• Natural hazards for the location: flood, storm, extreme heat, seismic, wildfire, sandstorm.
• Security and external events — intrusion, bomb threat, civil unrest, incident at a neighbouring site.
• Business disruption — loss of power, water, IT, communications, key supplier.
• Medical — serious injury, multiple casualties, outbreak, remoteness from definitive care.

Plan for the difficult combinations

Single-event plans rarely fail; combinations do. Plan explicitly for the awkward cases: an event at 3 a.m. with minimum manning; an event during a turnaround with 600 contractors on site; an event where the control room or the primary muster point is the location of the incident; an event where the site access road is blocked.

If the plan assumes the emergency will not damage the means of responding to it, it has not been tested against anything serious.