A New Combined Hazards and Risk Analysis Method for Automated Urban Transit

摘要

Unmanned automated urban transit systems such as metros and people movers require per standard (EN50126, ANSI/ASCE/T&DI 21-13) extensive hazards and risk analyses in order to first identify all possible hazards and second to follow up the resulting risks and their reduction to an acceptable level. Dresden University of Technology and TUV Rheinland perform and evaluate both kinds of analysis since many years and conducted several European Union research projects (e.g., MODSAFE) to obtain reference examples. Recent UTO-projects for subways in Germany were utilized to establish a more compact and practical method, responding to recurrent problems such as large size and readability, interface/link between hazards analysis and risk analysis, rates and their propagation in the analysis, links to safety requirement allocations/SILs. One especially tenacious subject is the question of how to deal with "continuous versus on-demand" mode functions: While a safety failure of the first kind presents immediate danger, on-demand-functions may not even be noticed that they could not be used anymore.