Part of the changes to the IEC61511 standard in 2016, some five (5) years ago now, was to emphasize the need to do a better job with regards to the Operations and Maintenance phase of the safety lifecycle. One of the key aspects of the Operation and Maintenance phase is in relation to assessing the performance of the Safety Instrumented Systems (SIS) in place. After all, the IEC61511 standard is a performance-based standard, so why wouldn’t we want to measure the performance? I am referring of course to the requirement in IEC61511 (yes, it is a requirement) to conduct a periodicFunctional Safety Assessment (FSA) 4. The IEC61511 standard requires FSA 4 but does not specify the frequency of conducting these and merely states that a sufficient period of time in operation should be used. This is, of course, highly subjective and open to interpretation, however, it allows the end user to choose the time period. If the plant has not experienced any issues, then the five-year period between revalidating the Hazard and Risk Assessment could be used. The idea being that the data gathered during the five years, could be used in the revalidation, since it will be based on actual field performance.
In my conversations with end users in the US, it seems that this is not something that is regarded highly and/or even considered! Why is it then, that in certain other countries around the world, the regulatory authorities (Australia for example), require end user companies to perform these activities? The whole purpose of conducting an FSA 4 is to ensure that the SIS and its Safety Instrumented Functions (SIFs) are performing according to the original design requirements to maintain the target risk reduction, as well as ensuring that the critical maintenance and mechanical integrity activities are being carried out.
Is it no wonder then that we are still experiencing industrial accidents! How would we know that our risk is being contained within our tolerable limits if we are not measuring the performance? The answer is simple. We will not!
Companies that come under the OSHA PSM requirements should be actively looking to have these assessments performed by experienced, independent third-party companies. Given the investment in the plant equipment, SIS and personnel safety considerations, it behooves companies to follow the requirements of IEC61511, which is defined by OSHA as being RAGAGEP (Recognized And Generally Accepted Good Engineering Practice). The FSA 4 is there for a reason and to help with the efficient and safe running of hazardous process plants. By using Key Performance Indicators to measure key safety metrics, such as proof test interval, failures, false trips, near misses, incidents, training, etc., we will have a better understanding of our overall performance.
If this blog has generated some interest, then look out for the upcoming webinar on the value of performing FSA4.