In layman's terms, Contingency Analysis (CA) is a 'what if' scenario simulator that evaluates, provides and prioritizes the impacts on an electric power system when problems occur. A contingency is the loss or failure of a small part of the power system (e.g. a transmission line), or the loss/failure of individual equipment such as a generator or transformer. This is also called an unplanned 'outage'. Contingency analysis is a computer application that uses a simulated model of the power system, to: • evaluate the effects, and • calculate any overloads, resulting from each outage event. Contingency Analysis is essentially a 'preview' analysis tool. It simulates and quantifies the results of problems that could occur in the power system in the immediate future. CA is used as a study tool for the off-line analysis of contingency events, and as an on-line tool to show operators what would be the effects of future outages. This allows operators to be better prepared to react to outages by using pre-planned recovery scenarios.