Functional Safety

Functional safety depends on a system operating in response to its inputs, including the safe management of likely operator errors, hardware failures and environmental changes.


Core has developed a suite of procedures which are based on IEC61508/11 which we can tailor to our Clients individual needs

The process of achieving functional safety must effectively address three distinct areas:

SPECIFYING: Safety integrity level (SIL) target

ACHIEVING: Design, construction, testing & validation to SIL target

OPERATION: Operation and maintenance in accordance with the SIL Target

For many Operators, the Specify (SIL targeting) phase is well executed but the Achieve and Operation phases can be poor. CORE can help assure all three areas are effectively executed and deliver true Functional Safety.


To facilitate the Functional Safety (FS) process Core has developed a suite of procedures which are based on IEC61508/11 which we can tailor to our Clients individual needs where required. We can provide guidance during every step of the Functional Safety lifecycle.

Core has FS experience covering a range of many different Clients needs, from assessing complete installations to small safety modifications and with Clients who have very well developed FS processes to those where these processes need putting in place. Our experienced consultants will provide guidance and advice on the best approach to take.


These following documents are the international standards for functional safety which have been adopted by the Oil and Gas Industry:

IEC 61508 – Functional Safety of Electrical//Electronic/ Programmable Electronic Safety-related Systems

IEC 61511 – Functional Safety – Safety Instrumented Systems for the Process Industry Sector

These standards define the overall Safety Lifecycle against which regulatory bodies ensure compliance.

SIL/LOPA/Risk Graph

A safety instrumented system can comprise single or multiple safety functions. Establishing the Safety Integrity Level (SIL) for each function involves establishing the combinations of failure of equipment and its controls which lead to Hazards.

It is then possible to analyse these hazardous failures in such a way that the risk targets can be met.

This in turn leads to the establishment of an IEC61508 SIL Target for each function. The two most common methods of SIL targeting are the Risk Graph (RG) and the Layers of Protection Analysis (LOPA).

RG provide a qualitative (quicker) method of establishing a SIL Target whilst LOPA is a semi quantitative method which provides a less conservative result.

Both methods require a review by a multidiscipline group with the actual offshore operators being key to the activity success. Data must be provided by the end user in the form of corporate information on acceptable risk criteria.

CORE takes a proactive approach to ensuring retention of our competent and well trained team of consultants.


All CORE consultants held accountable for functional safety engineering activities are Certified Functional Safety Engineers (CFSE) through attendance at an independently assessed TÜV approved training course.

Any functional safety related work completed by a non-certified engineer is approved by an appropriately competent CFSE. All CORE consultants who carry out functional safety engineering activities have as a minimum attended the Core Internal Functional Safety Engineering Programme.


In-house training is regularly delivered in key areas to ensure that knowledge pertaining to regulatory compliance, latest technical innovations and lessons learned are carried through to related scopes thereby benefiting all end users.


We’re here to help you with the day-to-day challenges you’re facing in your operations – get in touch to see how we can help.