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Dr. William Goble, CFSE

Most Failures are Systematic - NOT!

Wednesday, April 16, 2014 | Functional Safety Certification | Feed


Most Failures are Systematic - NOT!

We have studied hundreds of sets of field failure data from various sources here at exida.  Some of these data sets have indicated differences in failure rates by over an order of magnitude for the same product type.  After tracing through the data collection process for many of these field failure data sets, it is becoming clear that one significant variable is the question “What is a random failure?”

Very few failures are recorded in some data studies.  It was discovered in one study that many of the “possible failures” were classified as “systematic” and therefore not counted in the random failure rate.  In a January 2014…

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John Yozallinas, CFSE

Are You Building a Safer World?

Monday, April 14, 2014 | Functional Safety Certification | Feed


Are You Building a Safer World?

Every man takes care that his neighbor shall not cheat him. But a day comes when he begins to care that he does not cheat his neighbor. Then all goes well.”  - Ralph Waldo Emerson

I like to think about functional safety in a similar way.  We all want to be safe; it’s one of humanity’s primary needs.  But are we taking care to make our neighbor safe?

Functional safety standards IEC 61508 and IEC 61511 serve as a set of principles, techniques, best practices, and requirements to help us build a safer world.  Risks are analyzed, hazards are identified, and mitigation measures are developed.  Practitioners…

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John Yozallinas, CFSE

I Know My Requirements. Now What?

Monday, March 31, 2014 | Functional Safety Certification | Feed


I Know My Requirements. Now What?

If you’ve written your new product requirements, you probably understand exactly what they mean.  But will the other people on your project team?  You also probably understand that some unwritten requirements must also be met. They’re just common sense and everyone knows what they are. 

What about that new software developer who is a whiz at the computer stuff, but not so savvy about pressure transmitters? Requirements can be subject to interpretation and confusion.  Different parts of the organization speak different languages, literally or figuratively.  Marketing may know what the customer wants but engineering has to translate this information into a design.  A test engineer may have…

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Loren Stewart

Cycle Testing for Static Applications? NO!

Wednesday, March 12, 2014 | Functional Safety Certification | Feed


Cycle Testing for Static Applications? NO!

The failure rates of certain mechanical components used in solenoid valves, actuators, and valves vary substantially depending on operation. Seals such as O-rings, for example have fundamentally different failure modes when used in applications with frequent movement (dynamic) versus applications with infrequent movement (static). 

Static is generally defined as “stationary or fixed.”  We at exida define a mechanically static application as a low demand mode operation. Dynamic is generally defined as “energetic, capable of action and/or change, or forceful.”  exida defines a mechanically dynamic application as a high or continuous mode operation. 

Mechanical failure data can be found by four main sources:

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Dr. William Goble, CFSE

What is a “House Certificate?”

Tuesday, March 11, 2014 | Functional Safety Certification | Feed


House Cert

exida was recently auditing a systems level project per IEC 61511.  During such audits we check to verify that all equipment used in a safety instrumented function meets systematic capability by either IEC 61508 certification OR justification per reasonable IEC 61511 “prior use” criteria.  Most engineers at Refinery A choose the IEC 61508 certification route since that involves much less work and the certification provides stronger justification.

During the review of the IEC 61508 certified equipment, a few questions were asked:

  • “Are these Certification Bodies (CB) accredited to do functional safety certification per IEC 61508?”
  • “Is exida an accredited CB for functional safety per IEC 61508?”
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Dr. William Goble, CFSE

The Problem with the Expert

Wednesday, March 05, 2014 | Functional Safety Certification | Feed


THE PROBLEM WITH THE EXPERT

I recall the first time I was called an “expert.”  I thought that sounded nice. I spotted a magazine article on safety and thought “I do not have to read that as I am an expert.” I quickly recovered.  The real problem with being called an expert is that many forget how fast knowledge grows and they quickly become NOT an expert. Luckily I enjoy learning.  I spread out my advanced degree college education over many years at night school while working.  The degree was not the top priority as learning was fun but it was nice to get the degrees.  I did have a motivation issue after getting…

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Steve Gandy, CFSP

Ten Years Later

Wednesday, February 19, 2014 | Functional Safety Certification | Feed


10 Years Later

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 Safety Instrumented System (SIS) will now be halfway through their useful life.  This begs the question of how well have companies been recording the performance of their SIS systems, in terms of failures, spurious trips, and proof testing results?  IEC 61511 defines a safety lifecycle that covers the complete lifecycle for a SIS, including operation and maintenance.  Specifically, IEC 61511-1…

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John Yozallinas, CFSE

A Bug (Free) Life

Wednesday, February 12, 2014 | General | Feed


Bug Free Life

Can we really ship a bug-free product? That’s a tough question to answer.  Bugs originate in many places and not all bugs are the same severity.  But you can’t control what you don’t measure.  If you log and classify defects, and control the way changes are made, there may be some hope.  If not, make plans to start logging and classifying these failures.  Once you quantify this data, investigate the root cause of each failure.  Find out how it got there and what to do to prevent it next time.  Be sure to have a good change process in place to avoid introducing new bugs while trying to fix old ones. …

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Loren Stewart

Dare to Be Different

Monday, January 27, 2014 | Functional Safety Certification | Feed


LOREN STEWART

exida is often posed questions regarding our failure rates used in Failure Modes, Effects and Diagnostic Analysis (FMEDA) for products used in safety-related systems. 

Today I would like to focus on a question that was recently asked: “What if my products are unique or different than products typically used in a functional safety system?”  exida has a database which considers most failure modes options for components normally found in functional safety elements.  However, once in a while, exida does receive a request for certification from a customer with a product that is unique or uses new technology from other functional safety products.  If this is…

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Chris O'Brien, CFSE

Product Stewardship and Engineering Ethics

Friday, January 17, 2014 | Functional Safety Certification | Feed


Product Stewardship

Recently I witnessed something I never thought I would in the engineering profession: I was told by a system designer that even though they knew the safety reliability data for one device was too optimistic, they were going to use it because it meant they didn’t need to implement online diagnostics or redundancy. They could save money.  I had, until that point, maybe naively, assumed that when engineers used optimistic data they simply did not know better.

The crux of the problem is that there are two distinct world views when it comes to process safety reliability data. One approach is to leave it up to the equipment manufacturers to…

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Dr. William Goble, CFSE

Functional Safety, Cybersecurity, and Alarm Management in 2013

Friday, January 10, 2014 | Functional Safety Certification | Feed


FSAM

2013 was a good year for functional safety progress.  exida Certification issued a record number of new product functional safety certifications in mostly every product category - valves, actuators, solenoid valves, PLCs, fire and gas sensors, process sensors, and components.  The component category is one of the most interesting because it includes new microprocessors, integrated circuits, middle ware, operating systems, compilers, and even skid mount systems.  It is clearly becoming a simple task for any system level designer to find IEC 61508 certified instruments / components so that safety integrity can be assured.  Given the very weak “proven in use” justification documentation we have seen during IEC 61511 audits, it…

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Todd Stauffer

Know Your Value

Tuesday, January 07, 2014 | Functional Safety Certification | Feed


Typically a person’s salary reflects the value of their skillset and the importance of their role to their company. If that’s TRUE, then there is some good news for safety practitioners. A recent salary survey conducted by ISA and published in InTech magazine benchmarked the average salary by job function. It showed the average salary for safety systems engineers ($129,285) to be higher than all other job functions other than engineering management.  It also showed a significant increase in salary (5.9%) from the previous year.

average salary

So what does this mean?  It shows that companies are increasingly recognizing the value of safety practitioners. It also shows how important it is to…

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John Yozallinas, CFSE

12 Days of Christmas: Safety Edition

Tuesday, December 17, 2013 | Functional Safety Certification | Feed


What’s on your Christmas list?  Instead of relying on Santa, here are some gifts you can expect from a SIL 3 compliant process:

  • 12 safety requirements improved through review by test engineers
  • 11 validation tests that uncovered problems before they reached the field
  • 10 system failure modes discovered and mitigated through the use of architecture design review and FMEA
  • 9 software functions improved through code inspection and static analysis
  • 8 rules of software design followed for a structured, modular approach that leads to practical, understandable, and maintainable software modules
  • 7 software functions reduced in criticality due to software HAZOP analysis
  • 6 high failure rate electronic components replaced with lower failure rate

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John Yozallinas, CFSE

Developing a Functional Safety Product: What You Need to Know

Thursday, December 12, 2013 | Functional Safety Certification | Feed


Thinking about developing a safety product?  Use these 3 steps as a starting point:

1. Know thyself

Do you have documented development processes that govern how you develop a product from start to finish?  If not, start by writing down what is actually being done.  Interview the people who actually do the work.  Don’t worry if it seems off base, you can make adjustments later.  Once folks start thinking about what they do and how they do it, you should organize these steps according to the safety lifecycle.  If you have an ISO 9000 certification, this is a big help with overall process documentation, but it is not specific for functional safety.  You’ll have to review the…

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Ted Stewart

CFSE Endorsement:  Preparation and Achievement

Tuesday, December 03, 2013 | Functional Safety Certification | Feed


Click here to read Part 1 of this blog series

Click here to read Part 2 of this blog series

Passing an endorsement examination demonstrates proven capabilities and subject matter expertise beyond that which is required for the Certified Functional Safety Expert (CFSE) or Certified Functional Safety Professional (CFSP) credentials. The process of successfully earning an endorsement includes:

  • Complete a brief online application and registration
  • Select the specific area of endorsement for examination (e.g., SIL Verification)
  • Complete the online examination (40 multiple choice questions)
    • No travel necessary!  You may complete these exams from the convenience of your home or (if permitted) at your professional workplace
  • Score 80% or greater in the proficiency exam

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