SIL Classification is undertaken on safety instrumented systems for the purpose of defining a SIL rating for instrumented protective functions.

As competent SIL classification facilitators, we undertake exercises to advise and guide the classification team through the assessment process.

Classification methods can vary depending on the client, however the main objective being to determine likely hazards and consequences of failure against the instrumented protective function and relate this to a SIL rating in accordance with either client’s guidance document or recognised industry standard.

SIL Analysis is conducted to establish an integrity specification for system equipment, to determine whether the existing or proposed design meets the integrity specification and if not, what changes in design and/or the maintenance regime are necessary to meet the integrity specification.

In our analysis we adopt semi-quantitative and/or fully quantitative analysis generally specified in accordance with the client’s guidance document. Where this is not available, we are able to advise the best approach.

From our analysis we are able to advise if the hardware arrangement and current/proposed maintenance frequencies on each loop meet the Integrity Level requirements.

Failure data used in the analysis is taken where possible from clients own records. Reference is made when data is taken from other sources such as OREDA and PDS handbook.

Our personnel are conversant with recognised legislation / guidelines in this area such as IEC 61508/61511, API 14C and OLF 70.