How does the ISO rating work?

Insurance Services Office (ISO) is a company that performs many functions for the insurance industry. They develop and publish standardized policy forms for insurance companies to use. They also rate fire departments and publish these ratings for insurance companies to use in rating fire insurance polices. The process of rating fire departments involves investigating many factors including equipment used, response time, water pressure, fire hydrants, fire personnel, and other factors to determine ratings from 1-10 for fire departments.