New quantitative safety standards: different techniques, different results?

摘要

Safety Insturmented Systems (SIS) are usd in the process industry to perform safety functions. Many parameters can influence the safety of a SIS like system layout, diagnositcs, tesing and repair. In standards like the German DIN [DIN19250, DIN0801] no quantitative analysi was demanded. The analysis according to these standards is based on expert optinion and qualitative analysis techniques. New standards [IEC61508, ISA-S84] require quantitative risk analysis but do not prescribe how to perform the analysis. Earlier pbulications [ROU95, ROU96] have shown that different analysis techniques cover different aspects of system behaviour.