- by Loren Stewart, CFSE
- Tuesday, November 19, 2019
- Functional Safety
Back to Basics 17 - PFH (Probability of dangerous Failure per Hour)
PFH (Probability of dangerous Failure per Hour) is the probability that a system will fail dangerously, and not be able to perform its safety function when required. PFH can be determined as a probability or maximum probability over a time period of an hour. IEC 61508 and Read More...
- by Todd Stauffer
- Thursday, November 14, 2019
- Alarm Management
Evaluating Alarm System Performance in a Multi-Operator Control Room
Situation: There are three operator consoles (positions) in the same control room. There is one general alarm horn that goes off whenever a new alarm comes in from any one of the three consoles. The horn draws the attention of each of the three operators.
Question: How are the…
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- by Dr. William Goble, CFSE
- Tuesday, November 12, 2019
- Functional Safety
How Cars Relate to exida’s Site Safety Index (SSI)
I got a new car. The process was a bit disturbing. It took over an hour to go through the “set-up” menu. And it was suggested that I return for a second training session after spending time studying the manual and testing different settings. I was thinking how different things…
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- by Julia V. Bukowski
- Tuesday, November 05, 2019
- Certification
Guest Blog: Thar’s Gold in Them Thar Failure Data
Failure data collection can seem tedious, time consuming and expensive. Just figuring out what data to collect can be challenging. Failure data analysis can be overwhelming with a sense of “I don’t even know where to begin.” So it is not surprising that these useful, vital activities are often neglected especially when…
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- by Loren Stewart, CFSE
- Thursday, October 31, 2019
- Functional Safety
Back to Basics 16 - PFDavg
PFDavg (the average Probability of Failure on Demand) is the probability that a system will fail dangerously, and not be able to perform its safety function when required. PFDavg can be determined as an average probability or maximum probability over a time period. IEC 61508 and IEC…
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- by Jonathan Moore
- Tuesday, October 29, 2019
- Certification
Why Does My Risk Assessment Require an FMEDA?
If you find yourself faced with this question you might be wondering why it is that having successfully used risk assessments without FMEDA your team are suddenly faced with the complexity of executing FMEDAs.
Maybe us safety people answer with a follow…
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- by Steve Gandy, CFSP
- Thursday, October 24, 2019
- Functional Safety
PES Refinery – CSB Initial Report
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.
- by Iwan van Beurden, CFSE
- Thursday, October 17, 2019
- Industrial Cybersecurity
The Non-Hackable System – Wait a Minute, What?
I had the privilege to attend the CDS-forum in Trondheim, Norway on October 15, 2019. The CDS-forum is a Norwegian Industry Forum for Cybersecurity of Industrial Automation and Control Systems. The forum is a co-operation between oil companies, engineering oil companies, consultants, vendors and researchers, with a…
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- by John Yozallinas, CFSE
- Thursday, October 10, 2019
- Functional Safety
How Much Testing Is Enough?
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…
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- by Loren Stewart, CFSE
- Thursday, October 03, 2019
- Functional Safety
Back to Basics 15 - Architectural Constraints
Architectural constraints are limitations that are imposed on the hardware selected to implement a safety-instrumented function, regardless of the performance calculated for a subsystem. Architectural constraints are specified (in) according to the required of the subsystem, type of components used, and of the subsystem’s components. (Type A components are simple devices…
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- by Dr. William Goble, CFSE
- Thursday, September 19, 2019
- Functional Safety
My Final Element Field Failure Data says 150 FITS and OREDA is 2000 FITS
I got an email saying that the exida's www.SILSafeData.com minimum failure rates were way too high. The email went on to say that his REAL field failure data showed a result of 150 FITS for a remote actuated valve assembly. The lowest SILSafeData limits for clean service, Class IV leakage,…
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- by Ted Stewart, CFSP, exidaCSP
- Tuesday, September 17, 2019
- Certification
Personnel Certification Concerns? We are Here to Help.
A few weeks ago, we were asked to help a fellow colleague who received a message regarding their FS Engineer (TÜV Rheinland) certificate :
We are aware, that the validity of your FS Expert (TÜV Rheinland) certificate is expiring this month. Kindly be informed that we have had a…
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- by Steve Gandy, CFSP
- Thursday, September 12, 2019
- Industrial Cybersecurity
Are Your Control Systems Really Protected?
I don’t know whether you’ve noticed recently, but the number of cybersecurity alerts issued by CISA (Cybersecurity and Infrastructure Security Agency) seems to be increasing at an alarming rate. The latest alert I’ve seen now relates to GPS tracking systems for children. A device which is supposed to keep…
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- by Loren Stewart, CFSE
- Thursday, September 05, 2019
- Functional Safety
Back to Basics 14 - Systematic Capability
Systematic Capability is achieved when the equipment used to implement any safety function achieves two goals: the design process has used procedures intended to prevent systematic design errors (fault avoidance) and the design has systematic design control mechanisms such as a diagnostic for incorrect software execution (fault control). The rigor…
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- by Jonathan Moore
- Thursday, August 29, 2019
- Functional Safety
Let’s Talk About Configuration Management and ISO 26262
Most software developers are familiar with the need for and benefits of change control. Usually change control means one thing to a software developer and that is 'commits' to a source code revision control system. Not only do small and regular commits provide significant advantages to large teams of…
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