Quantifying life safety Part II: Quantification of fire protection systems

•Event-tree method to quantify the impact of protection systems on fire scenarios.•Development of models to incorporate protection systems within life safety analyses.•Compilation of probabilistic data for the systems to incorporate their failure.•Analysis of interaction effects between systems for cost–benefit optimization.•Discussion about a semi-probabilistic safety concept for life safety analysis.

In part I of the paper, an assembly building was analyzed in order to compute the failure probabilities, and thus the safety level, of current code-compliant buildings. In this second part, various fire protection systems are modeled within the fire and egress simulations in order to quantify their magnitude of impact. Since all fire protection systems can fail to perform as designed on demand, the potential failure along with its probability is accounted for in an event tree analysis. Comparing the resulting failure probabilities of the performance-based analyses with and without fire protection systems yields information about the magnitude of impact of the fire protection systems on the level of safety and hence allows a direct, objective, and quantitative comparison to other systems and designs. Accounting for the cost of the systems, a direct cost–benefit analysis can be conducted.