Coffee Break Training: Access and Water Supplies: Fire Flow Formulas: Part 4: Introduction to the Insurance Services Office Needed Fire Flow Formula [open pdf - 532KB]
"The ISO [Insurance Services Office] 'Guide for Determination of Needed Fire Flow' has been a recommended practice for calculating fire flow for many years. It is more complicated than the Iowa State University or National Fire Academy (NFA) methods but usually is employed when the fire department is establishing minimum flows for new construction rather than for emergency operations. It also is an important consideration in a jurisdiction's overall fire defense rating for insurance rates. The ISO developed its NFF [Needed Fire Flow] through historical review and analysis of large-loss fires. During the study, ISO reviewed the average fire flow that was delivered and evaluated other important factors such as construction type, occupancy, building area and exposures."
Coffee Break Training - Fire Protection Series No. FP-2013-39
United States Fire Administration: http://www.usfa.fema.gov/