Challenge to introduce MBSA approaches into CBTC safety analysis

Along with technology progress and fast paced development in China railway, the issue of safety is increasingly significant for all the involved technical equipments, especially for train control system. However, in view of the typical features of software-intensive, hardware-distributed, and communication-dependent derived from Communication based Train Control System (CBTC)¹, traditional safety analysis approaches gradually betray the deficiencies of loose consistency of safety and design processes and duplicate work on safety assessment. In this paper, two of prominent proposed model based safety analysis (MBSA) approaches: failure logic modeling and failure effect modeling are introduced to deal with these two industrially encountered challenges, and also a further feasibility study on system-component extraction and model boundary restriction is investigated via a lightweight CBTC case, to show key technical issues on deploying MBSA methodology into railway-specific safety critical system.