Hi all (again), I am currently working with a Client which has asked me to carry out a C&I compliance assessment on vendor skid coming from China. The skid is fair size (approx. 400m²) as it contains a full Pyrolysis unit along with it's own BPCS Control System and Independent Fail Safe Controller. Among all the other C&I compliance checks I am doing, the Functional Safety checks is one of the main items on my radar. My initial TQ's to this particular vendor contain queriers around how they have managed their SIL rated trips, i.e. which Safety Standard have they complied with? and also what lifecycle documentation they can provide, i.e. Hazard Study Reports, SRS, SIL Verification Calcs, SIF Validation evidence etc? (I am awaiting their response) .. I often hear that we should treat Vendor packages as black boxes, however I believe there must be some level of assessment which must be carried out by the Principal Designer to ensure the equipment being supplied is compliant to our standards, and has followed robust safety lifecycle? My question to the team is, what sort of assessment would you carry out on 3rd party skids the size of this? Again, any opinions on this one would be hugely appreciated!

A new case study has been added to the classroom. Scenario: A 1998 installed SIS with unknown diagnostic coverage is still in service. The asset owner believes it achieves SIL2 based on vendor documentation. Your task: Determine whether the claim is credible. Full case study here: [link] Questions: • What is the first thing you would check? • How would you deal with missing failure rate data? • Would you accept prior-use evidence?

Hi All, I am currently writing a proof test procedure for a High-High Temperature SIF. The sensor is 3-wire RTD. After carrying out all the proof testing checks, I have included for an RTD Calibration check to be carried out at the end, using a decade box or loop calibration device e.g. Fluke 754). Reason being, I wanted to ensure the loop was functioning correctly still after disconnecting sensor wires etc, during the proof test. However, my Client has requested this to be removed from the Proof Test as this is done as part of other existing maintenance routines. Just want to get anyone's thoughts on this, as to whether it is overkill to include an RTD check, and I should simply just ask the user to check the RTD is within it's prescribed calibration date? Any opinions on this would be appreciated!

Hi all. I would like to hear everyone’s views and opinions on having one valve for control and one valve for safety, Or if they would have one valve that does both. If you have one valve what’s are your argument for, independence, CCF, and control system errors.

Just added to the Resource classroom 👇 If you've ever had to explain functional safety to a Project Manager — or you are the PM trying to get your head around what your FSE is actually doing — this one's for you. The Functional Safety Cheat Sheet for Project Managers covers: ✅ Key terms in plain English — no jargon ✅ SIL levels explained in PM language ✅ The full safety lifecycle — what the PM owns vs what the FSE owns ✅ A quick decision guide — when to stop, when to proceed ✅ Top 10 things that derail safety projects ✅ Budget and schedule rule-of-thumb guidance ✅ Red flags to escalate to your FSE immediately It's designed to be handed directly to a PM at the start of a project so they can make faster, better-informed decisions without needing to read the standards themselves. Head to the Resource classroom to grab it now. 🔄 More resources being added regularly — we're just getting started.