【正文】 n the living room’ would have an impact on lowering the probability of fire occurrence。 ? This allows the fire protection engineers and regulators to assess the impact of these fire protection measures based on their assessments of the reduction of the probability of fire occurrence. Some of these residual probability multipliers can be obtained from statistics, if they are available. If no such information is available, then subjective judgment may be required. ? 火災(zāi)安全工程師基于火災(zāi)安全措施對火災(zāi)發(fā)生可能性的減縮情況來確定火災(zāi)安全措施的影響。 ? That is, the consequence of a ‘no smoking material’ plan is the reduction of the rate of fire occurrence to of its inherent value. ? Also in an eventtree method, the consequence of each fire scenario is assessed based on the inherent consequence of the fire and the impact of the various fire protection measures to minimize the consequence. ? In Figure , the impact of each of the fire protection measures on the consequence is assessed using a residual consequence multiplier. ? This allows the fire protection engineers and regulators to assess the impact of these fire protection measures based on their assessments of the reduction of the consequence. Some of these residual consequence multipliers can be obtained from statistics, if they are available. ? For example, NFPA statistics show that, based on the 1989–1998 data, the reduction in deaths in apartment buildings with sprinklers is 81% when pared with similar buildings without sprinklers (Kimberly and Hall, 2023). The residual consequence multiplier of a sprinkler system therefore is . ? That is, the consequence of installing a sprinkler system is the reduction of the death rate per fire to of its inherent value. ? If no such information is available, then subjective judgment may be required. For example, there is no statistical information that can be easily found on the death reduction benefit of implementing a ‘regular evacuation drills’ plan. Without such statistical information, we have to make an assumption again. ? Let us assume for this example that the residual consequence multiplier of a ‘regular evacuation drills’ plan is . That is, the consequence of a ‘regular evacuation drills’ plan is the reduction of the death rate per fire to of its inherent value. ? This residual consequence multiplier for each scenario is shown in Figure . For example, Scenario B has a residual consequence multiplier of , which is the product of (residual consequence multiplier of a failed sprinkler system) (residual consequence multiplier of a successful ‘regular evacuation drills’ plan). ? Figure shows the residual risk values of all the fire scenarios which are based on the success or failure of three fire protection measures. ? The probability value of each fire scenario is the product of the individual probability values of all the branches that are associated with that scenario. ? The residual probability multiplier of each scenario is the product of the individual probability multipliers of all the fire protection measures that are associated with that scenario. ? The residual consequence multiplier of each scenario is the product of the individual consequence multipliers of all the fire protection measures that are associated with that scenario. ? ? Finally, the residual risk multiplier for each scenario is the product of (scenario probability) (residual probability multiplier) (residual consequence multiplier). ? For example, Scenario E has a scenario residual risk multiplier of 10?03, which is the product of 10?03 (scenario probability) (residual probability multiplier) (residual consequence multiplier). ? In Figure , the multiplication of the residual multipliers is based on the argument, as discussed in Section , that each fire protection measure reduces the rate of fire occurrence, or the severity of the fire, or the death rate per fire, in succession by a certain percentage. ? It should be emphasized again that the values in the example are selected by the author as an example to show how such eventtree method can be carried out. In real risk assessments, these values need to be carefully analyzed and agreed upon by fire safety engineers and regulators. ? Subjective judgment of the probabilities and consequences provides a quick assessment of the potential fire risks. ? More fundamental and rational approaches to quantification, including the use of mathematical modeling of fire development and occupant evacuation, will be discussed in later chapters. ? Different from the checklist method, the eventtree method allows the summation of the risk values of all the fire scenarios into one single risk value for the whole system. This allows direct parisons of the risk values of various fire safety design options, including codepliant designs. ? Figure shows the bined residual risk multiplier of implementing these three fire protection measures is 10?1. That is, the residual risk is reduced to % of its inherent value ? The inherent fire risk values of apartment buildings can be obtained from statistics. For example, in Canada, the 1996 Canadian fire statistics (Council of Canadian Fire Marshals and Fire Commissioners, 1996) show that the total number of fire deaths in apartment buildings in that year was 88. ? Also, the 1996 Canadian census data (Statistics Canada, 1996) show t