I'm sure you are aware of the preliminary findings of the Philadelphia Energy Solutions (PES) Refinery explosion. If not, have a look at the video below. It is very interesting, but sad. I think we all can learn a lot from it.
I'm sure you are aware of the preliminary findings of the Philadelphia Energy Solutions (PES) Refinery explosion. If not, have a look at the video below. It is very interesting, but sad. I think we all can learn a lot from it.
It’s interesting that I had been preparing a webinar on pipeline safety and security since there have already been numerous incidents reported regarding pipeline accidents and leakage. Now the latest incident concerning Colonial Pipeline and the ransomware attack by Darkside, a so-called extortion group,…
How often do Managers see training budgets being cut, or personnel becoming blasé about training in general? Isn’t it the norm that annual performance reviews involve reviewing training requirements? Realistically, how often do these training requirements get ignored and/or forgotten about during the year? The answer, I’m afraid, is…
I saw and responded to a LinkedIn discussion on this very issue, where someone had asked “if I have a misaligned limit switch that fails dangerously, then is it random or systematic? “. This is an intriguing question because many view human error as being systematic and, whereas, this…
The IEC 61511 Standard requires the user to create a Safety Requirements Specification (SRS) for a Safety Instrumented System (SIS) that incorporates all the analysis done during the Risk Assessment, HAZOP/PHA and LOPA reviews. The SRS falls into two types: an initial conceptual SRS, often referred to as the…
It’s very interesting to me to find that people are still using excel to do PFD calculations. Whereas this is probably okay for simple single element architectures (i.e. single sensor, single logic solver and single final element), it becomes extremely complicated when dealing with redundant architectures. Moreover, for performing…
It’s hard to believe that the IEC61511 standard has been in existence since 2003, and most companies operating in the process, chemical, and refining industries (or any other hazardous process manufacturer) have adopted its practices. It’s also significant that any plants that were built back then with a…
It’s interesting that the majority of the time when people talk about functional safety, they are usually thinking about hardware: what sensors to use, which logic solver, what actuator, solenoid or valve to select; what voting architecture, etc. What often gets overlooked, initially, is the application program.
Essentially, when…
Common Cause is one of those variables that is not always considered important when it comes to SIL compliance. And yet, for redundant systems, it can have a significant impact on the PFDavg and Risk Reduction achieved (in Low Demand mode) or PFH (in high or continuous mode). Most of the…
The question of whether companies follow good site safety practices is an interesting one. Firstly, what do we mean by good site safety practices? I think most companies believe they follow good site safety practices but do they really? Are they really measuring and tracking this?
The basis of having good site…
This is an intriguing question. One that I often ask my classes when I’m teaching our FSE100 Functional Safety course. Very often, they do not know or do not fully understand what this means and why it is important.
The IEC61511 standard requires that any failures that occur within the…
I’ve been following some discussions from one of the online forums regarding competency and it’s clear from the correspondence that the issue of competency is still very subjective. It made me think about “what is competency?” To me it’s a blend of knowledge and experience and just how well…
When it comes to IEC61511 and the selection of equipment for use within Safety Instrumented Systems (SIS) and Safety Instrumented Functions (SIF), there are only two methods that can be used to justify selection: IEC61508 Certified devices for the required SIL or Prior Use Justification. Just…
The new release of IEC61511:2016 has caused some confusion when it comes to the Functional Safety Assessments (FSAs). Which ones are mandatory?
The confusion comes from the wording in the standard and the clarifications in the notes. The relevant clause in the standard 5.2.6.1.4 states:
A FSA team…
You may be wondering why this question is being asked? Isn’t it obvious that systematic issues are important and need to be considered? It may be that some of you reading this blog may not even understand what is meant by systematic issues. In which case, it may surprise you to know…
This was a question posed to me by an engineering contractor the other day. Although I found the question quite strange, it made me think “okay, why do they need us?” I suppose there are a few answers:
Cybersecurity incidents have shown that there can be major consequences for automation systems. There have been incidences where attackers have been able to manipulate the human resource interface console directly. It was only by chance that an operator in one particular instance happened to notice that his mouse pointer…
It’s interesting to note that with the release of the 2016 edition of IEC61511, there’s more emphasis being placed on the need for better functional safety management. Having taught many courses on Functional Safety over the past few years, I find that most of the…
This is a question I often get asked when I’m teaching our FSE100 course on Functional Safety, when we discuss the purpose of Proof Testing and coverage. It’s amazing how many end users assume perfect proof testing (i.e. 100% coverage), that is capable of finding, all the…
One of the fundamentals of the Probability of Failure on Demand (PFDavg) calculations in SIL verification analysis, is the concept of a constant failure-rate during useful life of the equipment. Probabilistic calculations assume that the failure rate of the devices used in a Safety Instrumented System (SIS)…