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John Yozallinas, CFSE

Building a Foundation for an IEC 61508 Development Process

Thursday, July 30, 2015 | Certification | Feed


There are organizations that are small enough to follow an informal or even undocumented process and still produce a product of sufficient quality to meet market needs.  When these organizations attempt to develop a safety product, they inevitably fall short of meeting the requirements of IEC 61508.  A formalized process that is reviewed and approved, along with project phase deliverables, are a major focus of the standard.

It can be hard to get buy-in from the development team…they just want to get something done.  As a starting point, you have to put some infrastructure in place.  ISO 9000 compliance is a good place to start, because a good quality management system (QMS) is…

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Dr. William Goble, CFSE

Getting Realistic Failure Rate Data - Part 5

Monday, July 20, 2015 | Certification | Feed


Over the course of several blogs , I will talk about getting realistic failure rate data, where this failure data comes from, and how different methods of failure data analysis compare. I think if you understand this, you will begin to get a very good feel of what it takes to generate realistic failure data. This is a subject I find very important and I hope you will find your time well spent reading this.

In Part 1,  I wrote about the fundamental concepts of functional safety standard for the process industries, IEC 61511. As well as the design phase of the safety lifecycle. In this blog, I will continue with talking about two fundamental techniques that have been developed…

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Dr. William Goble, CFSE

I Did Not Lock the Car Door

Monday, July 13, 2015 | Industrial Control System (ICS) Cybersecurity | Feed


I was driving one of exida’s top risk experts from Europe to a business meeting. We parked and I locked the car door.  He commented “I noticed you did not lock the car door when you parked at the exida office.” He was right. In an area I do not know, I always lock the car door.  But not always in the exida lot.  He added “A risk analysis will show car theft is a low risk due to random events, but remember cars are stolen by humans. These are not random events as we know them.”  He added “A good risk return on investment analysis would show you should always lock the…

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Dr. William Goble, CFSE

Getting Realistic Failure Rate Data - Part 4

Thursday, July 09, 2015 | Functional Safety | Feed


Over the course of several blogs , I will talk about getting realistic failure rate data, where this failure data comes from, and how different methods of failure data analysis compare. I think if you understand this, you will begin to get a very good feel of what it takes to generate realistic failure data. This is a subject I find very important and I hope you will find your time well spent reading this.

In Part 1,  I wrote about the fundamental concepts of functional safety standard for the process industries, IEC 61511. As well as the design phase of the safety lifecycle. In this blog, I will continue with talking about two fundamental techniques that have been developed…

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John Yozallinas, CFSE

That Could Never Happen! What are the Odds?

Tuesday, July 07, 2015 | Functional Safety | Feed


I often walk through my quiet neighborhood streets on weekday evenings or weekend mornings.  These are the times when I don’t expect much traffic, and my expectations are usually met.  The probability of a dangerous event that would injure me seems pretty low (risk assessment), since I am usually on the sidewalk and any cars are in the street.  However when I come to an intersection, I am constantly amazed how often one of the few moving cars on the street reaches the intersection at the same time as I do (demand condition).  Thank goodness for stop signs and low speed limits (layers of protection relying on operator, but no automatic safety function). …

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Dr. William Goble, CFSE

Can Wireless be used in Functional Safety?

Monday, June 29, 2015 | Functional Safety | Feed


exida just completed certification of a new sensor product that uses wireless communication to signal a safety logic solver of a potential problem.  Shortly after the certificate was posted, a challenge arose:  “How can wireless be used for safety?”  Well, it is different.  A designer must be fully aware of the different time response issues. The system must be configured to fail-safely upon loss of the wireless signal.  The system timeout must be long enough to deal with the redundancy of radio media.  But it is safe.  The protocols have been through careful analysis and will provide a safe message when the signal is good. 

“But what about security? I do not…

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Dave Johnson

Performing a Cybersecurity Risk Assessment as a Component of the PHA

Tuesday, June 16, 2015 | Industrial Control System (ICS) Cybersecurity | Feed


There are three main components of the safety lifecycle: analysis, realization, and operation. We will be taking a look at the analysis phase, particularly related to the cyber industry.

To start, the first thing to do in both safety and security is do a detailed process, hazard and risk analysis of the system. In the case of safety, you should allocate safety functions that will protect against those risks that you have identified and create a safety specification or set of requirements for each of those safety functions that you are going to apply. Once those requirements are in place, the realization phase is similar to other realization efforts, including design and engineering, acceptance testing and installation, and…

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Dr. William Goble, CFSE

Getting Realistic Failure Rate Data - Part 3

Wednesday, June 10, 2015 | Functional Safety | Feed


Over the course of several blogs , I will talk about getting realistic failure rate data, where this failure data comes from, and how different methods of failure data analysis compare. I think if you understand this, you will begin to get a very good feel of what it takes to generate realistic failure data. This is a subject I find very important and I hope you will find your time well spent reading this.

In Part 1,  I wrote about the fundamental concepts of functional safety standard for the process industries, IEC 61511. As well as the design phase of the safety lifecycle. In this blog, I will continue with talking about two fundamental techniques that have been developed…

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Michael Medoff , CFSE, CISA

The Evolution of Coding Standards

Monday, June 08, 2015 | Functional Safety | Feed


Sometimes it seems that things change slowly in the world of functional safety.  If you look at many of the technical references in IEC 61508 you will find that most come from the 1980s and 1990s.  There is even one reference that dates back to 1950!  With the rate technology is moving, the relevance of such old documents often comes into question.  The topic of programming languages is one area where change is constant, and a good example of this is C++11.  This latest version of C++ is already several years old, but it is starting to become important for functional safety.  The C and C++ languages have long been known for their…

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Dr. William Goble, CFSE

Getting Realistic Failure Rate Data - Part 2

Thursday, June 04, 2015 | Functional Safety | Feed


Over the course of several blogs , I will talk about getting realistic failure rate data, where this failure data comes from, and how different methods of failure data analysis compare. I think if you understand this, you will begin to get a very good feel of what it takes to generate realistic failure data. This is a subject I find very important and I hope you will find your time well spent reading this.  

In Part 1,  I wrote about the fundamental concepts of functional safety standard for the process industries, IEC 61511. As well as the design phase of the safety lifecycle.

In this blog, I will continue with talking about two fundamental techniques that have…

READ BLOG POST >>

Dr. William Goble's photo
Dr. William Goble, CFSE

Getting Realistic Failure Rate Data - Part 1

Monday, June 01, 2015 | Functional Safety | Feed


Over the course of several blogs , I will talk about getting realistic failure rate data, where this failure data comes from, and how different methods of failure data analysis compare. I think if you understand this, you will begin to get a very good feel of what it takes to generate realistic failure data. This is a subject I find very important and I hope you will find your time well spent reading this. 

IEC 61511 – Fundamental Concepts

IEC 61511 is the functional safety standard for the process industries.  When I read through IEC 61511, IEC 61508 , and the entire family of functional safety documents, I find that there are two fundamental concepts.

The first is…

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Denise Chastain Knight, P.E., CFSE

Close Enough? Not so Much

Wednesday, May 27, 2015 | Functional Safety | Feed


Performing a SIL Verification calculation on preliminary design information can be a very useful tool to dial in the Safety Instrumented Function (SIF), Safety Requirements Specification (SRS) content , and define critical elements for the field component purchase specifications. Conceptual verification is typically performed quickly with general design information. The objective is to gain confidence that the planned design will meet SIL target after detailed specification and procurement. Generalized suppositions are adequate for screening in many situations; however, there are circumstances where preliminary assumptions are not “close enough” to avoid last minute rework in order to achieve final verification. A savvy engineer learns how to adjust assumption to evade the “not so much”…

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Iwan van Beurden, CFSE

LOPAx™: This is Awesome!

Thursday, April 30, 2015 | Software | Feed


LOPAx

You will probably not hear me sing the LEGO® Movie’s “Everything is Awesome” song, I’ll keep that private (and you should be thankful to me for that). However as we just released the LOPAx™ module of the new exSILentia® v4 platform, I have come to the conclusion that what we have built here is, maybe even beyond, awesome.

As I was working on a new application exercise for our update functional safety engineering training course offering, FSE 101: Safety System Analysis, I wanted to include a HAZOP and LOPA example in that exercise for students to work on. As I’m writing the exercise, I’m working on the solution at…

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John Yozallinas, CFSE

Competency: Cutting Corners?

Wednesday, April 01, 2015 | Certification | Feed


Let’s turn our attention to home remodeling projects for a minute… literally cutting corners.

Most people are familiar with trim molding (baseboard and chair rail).  Laying out the trim on long flat surfaces is pretty easy: measure, cut, nail, paint… done.  Ok, sometimes it goes: measure, cut, measure again, cut the right length this time, nail, paint… done.  Some basic skills with woodworking tools are probably sufficient, but almost every room has corners.  Fitting the trim properly requires you to cut the trim at the appropriate angle.  A typical 90-degree corner is seldom a perfect 90 degrees.  The angle will vary slightly based on what kind of day your contractor is having.  You…

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John Yozallinas, CFSE

Texas City Refinery Explosion: Ten Years Later

Thursday, March 26, 2015 | Functional Safety | Feed


This week marks the 10th anniversary of the Texas City Refinery Explosion.  Is it any safer to work in the oil refinery industry since then?  That’s not an easy question to answer.  It’s difficult to get a yardstick out to measure safety.  But if we consider the number of deaths in the 10 years before the Texas City event and 10 years after, it is not much different: 64 vs 58 respectively.  Even counting deaths and injuries proved challenging due to a number of reasons: contract workers vs. employees, process safety vs. personal safety, counting methods by government vs. manufacturers, according to research by The Texas Tribune and the Houston Chronicle.

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