PD R009-001:1999

PD R009-001:1999 defines the interpretation and use of Safety Integrity Levels (SIL) in safety-related electronic systems for railway applications. The aim is to clarify the concept of SIL throughout the provision of:

• a methodology for the derivation of the safety process which is described in BS EN 50126 and based on SIL down to the elementary level in a structured and coherent manner
• a proposal for the correspondence between SIL and hazardous failure rates.