An early warning system (EWS) is technology and associated policies and procedures designed to predict and mitigate the harm of natural and human-initiated disasters and other undesirable events.
Early warning systems for natural hazards include those designed for floods, earthquakes, avalanches, tsunamis, tornadoes, landslides and drought. Other systems exist for a variety of events including missile launches, road conditions and disease outbreaks.The United Nations' International Strategy for Disaster Reduction (ISDR) recommends that early warning systems have the following four components:
Risk knowledge: Data should be systematically collected and analyzed and risk assessments performed.
Monitoring and warning service: Systems should be in place to monitor hazards and provide early warning services.
Dissemination and communication: Risk information and early warning messages must be delivered.
Response capability: Systems should be in place to respond to events.
In IT (information technology), early warning systems are used in a variety of environments. The Healthcare Alert Network (HAN) messaging system uses a variety of communication tools, including email, broadcast faxes, television and phone calls, to alert local, state and federal authorities and the media about urgent health threats and necessary actions. The SANS Institute refers to its Internet Storm Center, which tracks and reports on security threats, as an early warning system for the Internet. Social media analytics software can provide an early warning system for negative customer feedback, such as complaints about products or customer service. Early warning systems for data centers can be used to detect potentially dangerous conditions in the physical environment as well as in the hardware and software systems.