BAS CLC/TR 50451:2011

The scope of this Technical Report is to define a method to determine the required Safety Integrity Level of railway signalling equipment taking in consideration • the operational conditions of the railway, and • the architecture of the signalling system. From a mechanistic point of view the task of this Technical Report is to define a method of calculation, which determines the integrity requirements (qualitatively and quantitatively) from the inputs stated above.