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Safety Integrity Level

Safety Integrity Level is a measure of the risk to people and property that a system will experience during operation. The Safety Integrity Level is a qualitative measure of safety and it is expressed in terms of the consequences of failure. The higher the Safety Integrity Level, the lower the likelihood of failure and, therefore, the better the safety.

Safety Integrity Level study is a method to record all the SIF for a project development and document the expected reliability level. Safety Integrity Level study provides a basis for future maintenance and operating strategies. Safety Integrity Level assignment is based on the amount of risk reduction that is necessary to mitigate the risk associated with the process to a tolerable level. All of the Safety Instrumented Systems (SIS) design, operation and maintenance choices must then be verified against the SIL assigned.

Safety Integrity Level measure is based on how much damage could occur if an accident were to occur. SIL 1 indicates the least amount of risk, while SIL 3 indicates the highest risk.

Wire Consultancy offers comprehensive Safety Integrity Level

Wire consultancy is a highly rated Risk Engineering & EHS Solutions Consultancy company that offers Safety Integrity Level services. Wire consultancy consists of a diverse team of experienced auditors and professionals who have been working in the Safety Integrity Level field for over 20 years and have a deep understanding of Safety Integrity Level.

Wire consultancy has extensive experience in providing Safety Integrity Level services to companies across a range of industries, including aerospace, defense, oil and gas, transportation and medical devices. 

The primary objective of the SIL study is to determine the adequacy of Independent Protection Layers that are in place to mitigate against hazardous events relating to major process hazards.

The study will determine the risk reduction required for the SIFs such that sufficient Protection Layers or safeguards to allow them to meet the required risk reduction for a particular hazard. Quantification of the risk reduction requirements is given in terms of SIL requirement.

The key rule set for the Safety Integrity Level study is provided below

There are several methods used to assign a SIL. These are the normally used in combination, and may include:

  1. Risk matrices
  2. Risk graphs
  3. Layers of protection analysis (LOPA)

LOPA method for SIL classification has been utilized for SIL Study.

  1. Start permissive functions, simple alarm functions, ESD push buttons were not taken up for Classification as they are considered general protection layers and not SIFs in the strict sense.
  2. It was noted that all P&IDs, C&Es and other relevant documents were used during the SIL study.




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