Outcomes of the FRA:

When interpreting the outcomes of the FRA, NFPA 551 states that there are two ways in which the situation can be assessed to determine if it is acceptable.  First of all it can be assessed in a 'comparative' way.  The outcomes of the analysis can be compared with the situation that would be in place if the design of the building had completely complied  with  all  the  guidance.

Secondly,  the  outcomes  of  the  analysis  can  be assessed  'absolutely'. That  is,  they  can  be  assessed,  not  against  a guidance compliant design, but against simple acceptance criteria such as the desire to maintain a smoke layer at a certain height in an atrium or the desire to ensure that no one is exposed to radiative heat that would produce temperatures above 75oC.