Contingency Lifecycle

Contingency Lifecycle


The contingency lifecycle breaks down the stages of a contingency into normal operations; emergency situations; degraded modes of operation; service continuity; recovery to normal operations and (back to) normal operations.


The objective of the contingency lifecycle is to provide a common point of reference for all stakeholders to identify common stages in the progression from normal operations through the intervening stages back to normal operations again. It provides a structure for contingency planning.


In the context of the International Civil Aviation Organisation (ICAO) and European Community (EC) obligations, the concept of contingency can be organised along a “Contingency Lifecycle”. A diagrammatic presentation of the Contingency Lifecycle is presented below:


The horizontal axis shows the time. The durations of the different phases shown are not representative of the length of those phases. They could be very different from one event to another or from one environment to another. This Lifecycle should not necessarily be understood as a sequence of modes of operation. For instance, in certain circumstances depending on the cause/type of disruption:

  • A system (technical, people and procedures) working in 'normal' operation can evolve directly into an “emergency” situation; or
  • A system can deteriorate into a “degraded mode of operation” that further evolves into an “emergency” situation; or
  • An “emergency situation” can be followed by a 'service continuity' mode of operation.
  • In some situations, it might be necessary to move straight from 'normal' operation into a 'service continuity' mode of operation; or
  • The outage may lead to a disruption whose elapsed time is of days or weeks

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