exida

exida explains Blog

  • 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:

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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 Read More...

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…

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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…

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(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…

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  • 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…

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“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…

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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…

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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…

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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…

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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…

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To Be an Alarm…Or Not to Be?

  • 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…

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Do you have class?

  • by John Yozallinas, CFSE
  • Thursday, February 23, 2012
  • Certification

7 Ways to Keep your Auditor Happy

1. Name your files to make auditing easier; a filename with cryptic job numbers and abbreviations that are used within the company may not be easily understood or cataloged by an auditor

2. Give the auditor the ‘secret decoder ring’ for cryptic company acronyms and abbreviations

3. Have clear…

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