I am working on a SIL verification project and just had to share some observations.
For this project, the customer decided to choose a logic solver for which no data is listed in the exida Safety Equipment Reliability Handbook (SERH). One could…
exida explains Blog
- by Iwan van Beurden, CFSE
- Thursday, August 23, 2012
- Functional Safety
Super-Duper Logic Solver Data; So what?
- by John Yozallinas, CFSE
- Thursday, August 16, 2012
- Certification
Are You Going for Gold in Safety?
Olympic athletes don’t wake up one day and decide to compete in the Olympics. They don’t arrive at the games by chance or coincidence. Their journey starts long before the games begin. They are often influenced and inspired by watching others or by their own interests. They may begin…
- by Iwan van Beurden, CFSE
- Monday, July 23, 2012
- Software
Analysis and Realization: Done. Let’s Start Operation… What’s Next?
Congratulations! You’ve completed the Analysis and Realization phases of the Safety Lifecycle, and are about to begin the Operation phase, but what’s next? Well obviously you need to do proof testing, but is there anything else? You may be familiar with the figure below:
- by Steve Close
- Thursday, July 12, 2012
- Certification
Why should I get my mechanical device certified per IEC 61508?
I was recently approached with a question regarding why it would be necessary to certify mechanical devices, such as valves, per IEC 61508 when it is not clearly stated in the standard that the standard is applicable to such devices. After looking through IEC 61511 and
- by Hal Thomas, CFSE
- Friday, June 29, 2012
- Functional Safety
Relating Test Data to Operating Modes & “Proven in Use”
Everyone wants data, and generally everyone agrees high quality proven in use data is the best. Properly designed experimental testing is one means to simulate actual operation. That is what we all learned as far back as high school during our chemistry and physics labs. These tests can…
- by Michael Medoff , CFSE, CISA
- Thursday, June 21, 2012
- Industrial Cybersecurity
A False Sense of Security
About 5 years ago I was sitting around a big table in a conference room at a major LNG terminal. Outside the window I could see a big city harbor filled with boats, bridges, sky scrapers and approximately 5 million people. I could also see two huge LNG storage…
- by John Yozallinas, CFSE
- Thursday, June 07, 2012
- Industrial Cybersecurity
(Almost) FREE Security Training
The Department of Homeland Security (DHS) is tasked with many things. One area of focus is Industrial Control Systems (ICS). The Industrial Control Systems Joint Working Group (ICSJWG) was formed to facilitate this focus. This group holds semi-annual conferences (Spring and Fall) in various US cities. These meetings…
- by Dr. William Goble, CFSE
- Thursday, May 31, 2012
- Certification
DANGER, DANGER, DANGER!
Assumed 10 Demands Per Year
During a SIF verification calculation review this week, the engineer pulled out a safety certificate with very low failure rates for a solenoid valve. Certificate No. V139 2009 C4-4 [1] states that a solenoid valve has a dangerous failure rate of 4.57…
- by Michael Medoff , CFSE, CISA
- Thursday, May 24, 2012
- Industrial Cybersecurity
“Building Security In”
Cybersecurity continues to be a big problem for the world at large and for control systems specifically. The amount of time and effort that it can take to simply keep all of the security patches up to date on a large control system can be mind boggling. No…
- by Dr. William Goble, CFSE
- Thursday, May 17, 2012
- Functional Safety
The Battle of the Failure Rates
Site Specific vs. Product Specific
During a field failure analysis study, it was discovered that the calculated failure rate of a specific device varied by more than 4X depending on installation site. Particularly, it was one specific site with a high failure rate. While any reliability engineer…
- by Dr. William Goble, CFSE
- Friday, May 04, 2012
- Functional Safety
I Don’t Want No D*** Diagnostics!
After a false trip incident, I heard a control engineer express his displeasure with the automatic diagnostics in a new safety rated transmitter. The transmitter diagnostics were annunciated by sending the analog current out of range. In this case, the current went to 3.6 milliamps. The problem was that…
- by Dr. Eric Scharpf, CFSE
- Thursday, April 26, 2012
- Functional Safety
The Safety Lifecycle as a Risk Control Loop
I have been doing a number of recent projects introducing the safety lifecycle to companies that are new to the field. As a result I have been playing with various ways to think about the overall safety lifecycle philosophy. As many of the more experienced readers are…
- by Chris O'Brien, CFSE
- Friday, April 13, 2012
- Certification
Too Good to be True
A.K.A You’re About to Severely Under-Design your SIF and Put your People at Risk. Twice this week alone, and much more often than I like to remember, I’ve had safety system designers blindly follow certificates that contain data that simply cannot be true. They get a certificate from…
- by Todd Stauffer
- Thursday, March 22, 2012
- Alarm Management
To Be an Alarm…Or Not to Be?
That is the question.
When your alarm does not meet the definition as defined in the ISA-18.2 standard and/or the criteria established in your alarm philosophy document, it is not an alarm.
By ISA-18.2 definition “an alarm is an audible and /or visible means of…
- by John Yozallinas, CFSE
- Thursday, March 15, 2012
- Certification
We’re Only Human
We’re only human. Most of the time, that is a good thing. But humans seem to accept more risk over time when nothing bad has happened. We lose our vigilance. We take more chances. A close call might only be remembered as an unusually rare anomaly instead of a…