Contingency planning is the preparation undertaken to deal effectively with an exceptional or unforeseen risk that is impossible to avoid. These plans are often devised by organisations that want to be prepared for events which may be highly unlikely, but which would have a major impact in the event of their occurrence. For example, the reliance on a single source could have major implications for business continuity in the event of disruption to supply. Disaster recovery and business continuity planning are related activities focused on developing foresight and allowing quick response. See also Disaster Recovery and Risk.