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INNOVATIVE TECHNOLOGY

Risk analysis. Key concepts GOST R IEC 61511
The standard GOST R IEC 61511 operates with two key concepts:
1) safety life cycle;
2) SIL safety integrity level.
The SIL, on the one hand,
determines the necessary reduction in
the risk of a potential accident due to
the use of a protection circuit based
on the EAP system, and on the other
hand, determines the requirements
for the safety indicators of the circuit
itself: the average probability of failure
when requesting a shutdown (PFDavg),
hardware redundancy for safety
function (HFT). The general concept of
risk reduction is presented in Fig. 1, SIL
applies to part of the risk eliminated by
the SIS. The safety life cycle defines
a set of stages, works and methods
of control and verification (Fig. 2).
Fig. 1. General concept of risk reduction GOST R IEC 61511, where SIS - Consider each of the stages of the life
security instrument system, EAP system - a special case of SIS.
cycle in more detail.

Fig. 2. Security life cycle.

Risk Analysis Phase
It is carried out using one of the methods, for example, hazard and operability analysis
- HAZOP (Hazard and Operability study). At this stage, the following are considered: dangers
associated with deviation of the technological regime; their causes, as a rule, are the failure
of controls; the consequences of such deviations; existing methods of protection and the

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