A contingency plan is a methodical approach to preparing for potential events. The planner performs a risk analysis of various scenarios and their probabilities. Based on the risk analysis, the planner designs contingency plans detailing how each scenario is responded to. Contingency plans boil down to two major types: staying in place or evacuating.
Plans to Stay In Place
Low-intensity scenarios where there is no immediate threat to the planner's location allow the person to stay in place. Initial plans involve the creation of what the Federal Emergency Management Agency calls a three-day kit. The kit contains enough food, water, and medical supplies for each person during that time period. The concept is that during a disaster, basic services and support from the government are not available for several days. The three-day kit allows each person to survive until those services are restored. Planners can increase the amounts of food and water for scenarios of longer duration.
Plans to Evacuate.
Scenarios that require evacuation have different goals. Colloquially known as a "bug out" plan, the planner designs responses for contingencies that require evacuating the current location. The planner considers transportation, food, water and shelter. Where to evacuate to is another concern. Access to cash or other amenities must factor into the contingency planning.
Blending Contingency Plans
Some scenarios require a blend of the two major contingency plans. A situation can require that the planner remains until it is safe to leave. Weather, issues at nuclear power plants or other problems make it hazardous to venture outside. Staying until it is possible to evacuate minimizes the danger factor to the planner.
What to Plan For
The planner must plan for reasonable scenarios starting locally. Plans in regions where hurricanes or other severe weather is prevalent are different from plans in areas where earthquakes are more common. Planners should focus first on potential local events, then expand the plans to regional or even potential national level events.