Hazard Identificaiton of Railway Signaling System using PHA and HAZOP Methods

초록

Railway signaling system requires the high level of safety since these have to ensure safe operation of the train. According to these reason, safety-related regulations for railway signaling systems are internationally standardized. To secure the safety required by international standards, the hazard control is necessary with system lifecycle, and the hazard identification is needed to hazard control. To draw this hazard which is the basis of whole hazard control, there are very many techniques such as PHL(Preliminary Hazard List), PHA(Preliminary Hazard Analysis), HAZOP, FMEA(Failure Mode Effect Analysis), etc. in the activities and methods. The PHA and HAZOP method is recommended for hazard analysis at IEC standards, but this method has several unsuitable problems to apply to railway signaling system. In this paper we recommend the modified HAZOP method, which would be suitable for analyzing safety of the railway signaling systems. And also an example of PHA and this method applied to real system is also included.