Ehh… If your safety action is stopping flow/closing a valve, how are you going to accomplish this if you consider that the remote actuated valve is not part of your SIF ?
So, what is this myth based on? The title of IEC 61508 reads “Functional safety of electrical/electronic/programmable…
Functional Safety and Electromagnetic Interference (EMI) may not often be used in the same sentence. But EMI is just one of the environmental stresses that can stop a system from performing its safety function. It is important for a functional safety system to be immune from the EMI levels…
Today, April 15th, is tax-day in the US. Ok, the Internal Revenue Service (IRS) has given us a few extra days this year (the tax filing deadline is not until April 18th).
There are a lot of similarities between how you do your taxes and how you handle…
Protection systems have been around for a long time, going back to having a canary in the mine, and throughout the Industrial Revolution; so they are not a new thing. Various stakeholders were involved in business enterprises: owners, suppliers, consumers, community members, and workers. Usually the business owners held…
This is an important question. Mining today is a lot more modernized and automated than in the past, yet there are still accidents occurring. The Impala hoist accident in South Africa in November of 2023 is an example, where there was a tragic loss of life when the hoist…
IEC 61508 is considered a basic or “umbrella” standard for functional safety. It is generic and sometimes even vague. IEC 61508 was intended that various industry sectors provide their own specific standards and guidelines as needed. Here we can see the relationship between 61508 and other standards, such as…
This is a question I’ve been asked many times, with some stating that as long as the PFDavg (or PFH) meets the target SIL then that’s fine. Whereas this statement is partially true, it is not the full answer. IEC61511 defines the criteria for meeting the requirements of an…
I was reading an incident report on the Chemical Safety Board (CSB) website the other day, where it was the conclusion of the reviewing team that the incident (which sadly resulted in a loss of life) was the direct result of a poor safety culture across the…
Oftentimes when this comes up during class it’s clear that there’s a misunderstanding as to how these three variables can impact the PFDavg calculations. Mission Time is defined as the period of time over which a set of Safety Instrumented Function (SIF) equipment is expected to operate without major…
Have you ever wondered if you tested your product enough? Either in enough ways or for a long enough time? This assumes that you’d prefer to discover all the problems before your customers do. If you follow a 61508 compliant development process, you should be able to…
Formalize your process.
Companies often have a pretty good hardware development process in place, dealing with electrical and mechanical drawings, bills of material, and the factory floor interface. Most of these processes are in place so the manufacturing department knows what to make and how to put it together. …
There is no shortage of drivers who try to “beat the red light,” or roll through a stop sign. I see it every day (luckily BEFORE they hit my side door). Even though everyone knows, or should know the “rules of the road,” there are some folks who are…
Your organization gets information, feedback, and requests from customers all the time. It’s up to you to do some preliminary analysis and determine what the customer really wants. Do they want to buy something? Do they want to complain about something? Do they have a need for which no…
Some of you reading this may not be aware or familiar with the terms “leading” and “lagging” indicators, when applied to Functional Safety. The concept isn’t new but does provide significant benefit when applying this to Functional Safety because, if used correctly, these indicators can help significantly improve performance. …
The machine safety community has defined a number called the “B10 number.” It is a measure of time where 10% of a population of devices should have failed. Generally it is a measure of expected end of life or “useful life” as defined by the reliability engineering community.
The…
When I first heard this phrase, I was working in an R&D group developing electronic DCS. My first interpretation was that until the Sales Department got an order for a new product, new ideas sort of sat on the shelf with low priority… meaning that people were probably working…
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.