The ISO rating system analyzes the capability of community fire protection services and assesses risk for the purpose of setting fire insurance premiums, according to Appen Media Group. The Insurance Service Office develops a numerical score for each community called the Public Protection Classification.
The ISO rating reflects the evaluation of a community's fire department, emergency communications, water supply and fire safety education. The scores are published in the Fire Suppression Rating Schedule used by insurance companies. The FSRS underwent a major revision to improve its methodology in 2012, and the change has been approved by a majority of states as of 2015, according to ISO Mitigation.