DEDUCTION OF SAFETY FUNCTIONS IN THE TRAIN CONTROL SYSTEM

초록

Nowadays railway system is operated by driverless or automatic operation. In this situation, the safety is more important and has to be accomplished. The first task to accomplish the railway safety is to derive safety functions of a specified system. The safety functions are deduced by safety analysis. In order to perform the safety analysis, the system hazards have to be identified using HAZOP(Hazard and Operability Studies) or FMEA(Failure Mode and Effect Analysis), etc., and risk analysis for each hazard should be performed. The risk is related to the frequency and the severity factor of each hazard. And then countermeasures for each risk have to be prepared using PHA(Preliminary Hazard Analysis), etc. The summary of the countermeasures is a kind of safety functions in a system. In this paper, safety functions of railway system are derived following the upper procedure.