【正文】 e discussed in later chapters. ? EventTree Method ? An event tree is another way to identify potential fire hazards, assess their probabilities and consequences, and arrive at risk values. Different from the checklist method, an event tree shows more than a list of potential fire hazards and fire protection measures for the assessment of the probabilities, consequences and eventually the risk values. ? The eventtree method involves the construction of an event tree of various fire scenarios subsequent to the initiation of a fire hazard, as described in Chapter 2. The fire scenarios provide more logical information for the judgment of probability, consequence and risk values ? . An example of an eventtree method employing quantitative fire risk assessment is shown in Figure . This is the same example that was used in Chapter 4, except that quantitative assessment is employed rather than qualitative assessment. ? In Figure , the branching to different events depends on the success or failure of the fire protection measures in place. ? This example looks at one fire hazard in an assumed apartment building and the consideration of a number of additional fire protection measures to minimize the risk. ? The same event tree can be constructed for more hazards and more fire protection measures. A plete fire risk assessment would involve the identification of all potential fire hazards and the consideration of various fire protection measures to minimize the risk. ? A typical apartment building usually has some fire protection measures, such as fire resistant construction and fire alarms. Additional fire protection measures would lower the risk further. This example considers the same six different binations of three additional fire protection measures which were considered in the checklist method in Section . ? The three additional fire protection measures are: ? (1) no smoking material (such as cigarettes) in the apartments, ? (2) sprinklers and ? (3) regular evacuation drills. ? Each of the three fire protection measures has an impact on either the probability of fire occurrence or the consequence of a fire occurrence. ? For example, the measure of ‘no smoking material in the apartment’ would have an impact on lowering the probability of fire occurrence。如圖 ，每一種火災保護措施對火災發(fā)生固有頻率的影響通過一個殘余可能性因子來體現（ residual probability multiplier ）。比如 Scenarios A, B, C, D， “在公寓中使用阻燃材料”全部失敗，殘余可能性因子為 1，意味著沒有減少火災的發(fā)生；而 Scenario E, F, G, H,“在公寓中使用阻燃材料”成功，具有的殘余可能性因子為 ，即火災發(fā)生的可能性，降低到固有值的 。 ? 我們只能對此進行假設，在本例中假設“在公寓中使用阻燃材料” 與“在建筑中禁煙”對火災發(fā)生可能性的影響相同，其殘余可能性因子為 (見 Table )。 ? 2. by using an event tree to go through a set of potential fire scenarios and the quantitative assessment of their fire risks. ? In both these methods, the values for the probability and consequence parameters are obtained from statistical data, if they are available, or from subjective judgment, if such data are not available. ? (僅在我們本課程的講解中，采用了統計或主觀估計的方式，火災的結果還可以通過確定性的分析計算獲得 ) ? Checklist Method ? As was discussed in Chapter 4, the checklist method employs the creation of a checklist of potential fire hazards and the consideration of fire protection measures, either in place or to be added, to arrive at an assessment of the fire risks. ? The creation of a checklist of potential fire hazards allows a systematic check of potential fire hazards that are in place. ? The listing of fire protection measures alongside with the potential fire hazards allows a quick check of any safety deficiencies and any need to provide additional fire protection measures to minimize the risk. ? The checklist method, therefore, is an enumeration of potential fire hazards, fire protection measures, either in place or to be added, and the assessment of the residual fire risks. ? It is used to identify any deficiencies and any corrective measures needed to minimize the fire risks. ? It does not include, however, the consideration of the logical development of fire events, which will be discussed in Section using an event tree. ? An example of a checklist method employing quantitative fire risk assessment is shown in Table . This is the same example that was used in Chapter 4, except that quantitative assessment is employed here rather than qualitative assessment. ? This example looks at a potential fire hazard in the living room of a house and the consideration of a number of additional fire protection measures to minimize the risk. ? Obviously, there could be many potential fire hazards in a house. ? A plete fire risk assessment would involve the identification of all potential fire hazards and the consideration of various fire protection measures to minimize the risk. ? A typical house usually has some fire protection measures, such as smoke alarms. Additional fire protection measures would lower the risk further. Similar to the example in Chapter 4, this example considers six different binations of three additional fire protection measures. ? The three additional fire protection measures are: ? (1) no smoking material (such as cigarettes) in the living room, ? (2) sprinklers ? (3) regular evacuation drills. ? Each of the three fire protection measures has an impact on either the probability of fire occurrence or the consequence of a fire occurrence. ? For example, the measure of ‘no smoking material i