System Safety Factor : The weakest point within a system, expressed as a ratio between the minimum breaking strength of that point (component) as compared to the force placed upon it
NFPA 1670 Standard on Operations and Training for Technical Search and Rescue Incidents, 2009 ed. https://www.nfpa.org/assets/files/AboutTheCodes/16 70/Errata1670-09-1.pdf, (Std: Opr and Trng for Tech Search and Rsq Incid - Amer) {408 NFC}