SIL Allocation of APM Based on MODSafe Method

Objective APM (automated people mover) has very high requirements for safety, and the existing SIL (safety integrity level) allocation method cannot meet the demand of APM projects efficiently and accurately. In order to ensure the safety and reliability of APM, further in-depth research should be conducted on the allocation of SIL and the determination of the safety targets for APM. Method The existing methods for SIL allocation in APM are elaborated, and a widely recognized method MODSafe (modular urban transport safety and security analysis) is proposed and applied for SIL allocation of APM. The basic steps of the MODSafe method are introduced, and the respective SIL allocation steps are clarified under the two modes of high and low safety demands. The technical idea for conducting SIL allocation based on MODSafe method is further elaborated with the train jerk control function of APM as the example. Result & Conclusion Identifying safety functions and determining safety targets in the initial design phase is crucial for the safe delivery， operation and other aspects of APM projects. The MODSafe method can be used to quantitatively determine the THR (tolerable hazard rate) and SIL of APM safety functions.