基于BDD的铁路快运货物损失风险评估
Risk evaluation for railway express cargo loss based on BDD

摘要 为了更科学地分析评估铁路快运货物在途安全风险，将二元决策图（Binary Decision Diagram，BDD）应用到风险故障树分析（Fault Tree Analysis，FTA）中，构建铁路快运货物损失风险评估模型.通过对快运货物损失情况统计，分析得出货物发生损失风险的直接因素，建立风险故障树.利用香农（Shannon）分解和ite结构选用合适的事件排序方法将故障树转化为BDD.以快运货物损坏风险为例，遍历BDD每个节点计算得出各底事件的概率(Birnbaum)测度和顶事件的发生概率，与FTA方法计算结果对比验证了该方法的正确性及在计算效率方面的优势.实验结果表明:包装质量、恶劣天气和货物对环境的高要求是导致铁路快运货物损坏的关键因素，并对此提出相应的改进措施.
Abstract：To scientifically deal with the safety risk of railway express cargo in transit, Binary Decision Diagram(BDD) is applied to the risk Fault Tree Analysis(FTA) and constructed the risk evaluation model of railway express cargo loss. After analyzing the statistics of express cargo loss, the direct factors of the loss risk of express cargo are obtained and the risk fault tree is established. Using Shannon’s expanded theorem, if-then-else structure and appropriate event sorting method to transform the fault tree into a BDD. Taking the damage risk of express cargo as an example, the Birnbaum importance of bottom event and the risk probability of the top event are calculated by traversing each node of the BDD. Comparing with FTA, the experiment results show the correctness and its advantages in computational efficiency of BDD. According to the calculation results, packaging quality, adverse weather and high environmental requirements are the key factors which lead to damage to railway express cargo. Finally, the corresponding improvement measures are proposed.