Good Morning All, Just to let you know the 61508 Association are holding a conference in York on November 25th this year. The event is free to join and looks to include a very good agenda regarding Functional Safety Compliance. I have attached the flyer for those that are interested 🙂

Quick update — I’m feeling a bit under the weather this week, so I’m going to reschedule our deep dive review session to make sure I can give it the energy and focus it deserves. I’ll post the new date and time once I’m back on my feet — aiming for Friday if all goes well. In the meantime, if there’s a specific topic or question you’d like me to cover in that session, drop it in the comments below so I can build it into the updated plan. Appreciate your understanding, and I’ll catch you all very soon. – Richard

Hi All, Just read an interesting article on the recent introduction of an ISA standard which provides guidance on the management of Independent Protection Layers - Low Integrity Protection Layers: ANSI/ISA-84.91.03-2025 Explained. This is an interesting subject as IPL's are an essential aspect when working out the target RRF of a SIF, however they are often forgotten about once the plant goes back into operation. Some sites do manage the maintenance of IPL's differently to non-safety loops, via a maintained IPL register, IPL validation and more stringent testing routines. However this is not always the case and a lot of the time IPL's just fall into the normal maintenance system as this article suggests. Would be interesting to hear from the group your thoughts on this subject .....

Hi all, With regards to carrying out an FSA 5 assessment, is it deemed necessary to carry one out if you are only adding new SIFs into an existing Safety Logic Solver. In this example, the new SIF to be installed does not share any of the same elements (other than the logic solver) as any existing SIF's, and also the new SIF has no impact on any existing SIFs? My thoughts are no, but just wondering if anyone else can clarify if I am correct?

My proposed topic for discussion: I have experience in conducting a SIL requirement assessments for furnace burning systems. Each client of such analyses have a little bit different approach and risk assessment procedures which I should follow. However as an analyst and session leader I don't agree with them sometimes. It is always a challenge for me, as analyzing such a system raises many questions about the validity of decisions made during the LOPA. Briefly: This particular protection system consists of many instrumented safety functions protecting the furnace, like low and high pressure of the fuel gas, low pressure of combustion air, loss of flame, overpressure in the combustion chamber, wrong air/fuel ratio, CO/O2 flue gas detection, flue gas damper closure detection and some others depending on specific technology used. So the first issue of this SIL analysis is related to the layers of protection. In the most conservative case, we can't take any additional layers of protection independent of the analyzed function. Why? Because all possible other actions are still the same: close the double shutoff valves at the fuel supply line to the burners. The same valves which are part of the SIF we are talking about. What's more it's not always possible to ensure a low personnel presence rate in the hazardous area. This of course results in very high SIL requirements. But I always wonder if this approach is practical and not too conservative? The second question is whether each of these SIFs really needs to be analyzed separately, when most of them protect the furnace from loss of flame and a chamber from the formation of an explosive atmosphere. Perhaps some functions can actually be considered as a one SIF with redundancy and diversification of measurement systems detecting different physical quantities? This case is much closer to my approach of practical side of functional safety. By the way, I've got also a third point of view but maybe I will describe it a little bit later during a discussion.