exida explains Blog

How is SIL Used?
  • by Loren Stewart, CFSE
  • Tuesday, September 22, 2015
  • Certification

How is SIL Used?

Click here to read the first entry in this blog series 

Once the Safety Integrety Level (SIL) of a product is found, it will be used FOUR ways:

  1. To establish risk reduction requirements
  2. Probabilistic limits for hardware random failure
  3. Architectural constraints 
  4. Read More...

What is SIL compliance?

What is SIL compliance?

The Safety Integrety Level (SIL) of a product is determined by three things:

  1. The Systematic Capability Rating
  2. The  Architectural Constraints for the element
  3. The PFDavg Calculation for the product

The Systematic Capability Rating

Systematic Capability is established by having your quality management system audited per IEC 61508.…

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Return to the “Just Do It” Approach
  • by John Yozallinas, CFSE
  • Tuesday, September 15, 2015
  • Software

Return to the “Just Do It” Approach

*The “Just Do It” approach was previously referenced in the blog entry Seat-of-your-Pants Software?

If used early in the development lifecycle, a “just do it” approach could help marketing determine the look-and-feel of an application program with a complex user interface.  Early software prototyping on a PC…

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What’s Your Biggest Fear?
  • by John Yozallinas, CFSE
  • Friday, September 11, 2015
  • Certification

What’s Your Biggest Fear?

Plane crash?

Earthquake?

Ebola outbreak?

Shark attack?

There are probably lots more things to add to that list.  What could we do to prevent them?  Not too much for some… a little more for others.  But would those mitigations be practical?  What tolerable risk can we accept for these…

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To Spreadsheet…or NOT to Spreadsheet
  • by Dr. William Goble, CFSE
  • Thursday, September 03, 2015
  • Software

To Spreadsheet…or NOT to Spreadsheet

I remember the first time I ever saw a spreadsheet program. It was called “VisiCalc" and ran on a Commodore PET computer. My first thought was, “What is that good for?” Then I tried it and was totally hooked. I conclude that the creation of the spreadsheet has changed…

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What is Systematic vs. Random Capability?
  • by Loren Stewart, CFSE
  • Tuesday, September 01, 2015
  • Certification

What is Systematic vs. Random Capability?

There seems to be a bunch of confusion surrounding systematic capability and random capability.  I will try to clear up the confusion by explaining what is all considered and what the IEC standard says about both. 

Systematic Capability

  • Development process/quality system requirements depend on certification SIL level, higher…

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The Architectural Constraint Blind Side
  • by Denise Chastain Knight, P.E., CFSE, CCPSC
  • Thursday, August 27, 2015
  • Certification

The Architectural Constraint Blind Side

I did my homework, purchased certified devices, and specified physical redundancy. I expected an uneventful SIL Verification but the assessor is telling me that I have functions failing Architectural Constraints in the sensor and final element groups. How can that be? 

Low demand mode Safety Instrumented Function (SIF)…

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Failure Rate Data: Are You Being Outsold?

Failure Rate Data: Are You Being Outsold?

When speaking with several manufacturers’ sales teams recently, it became very evident that some of these sales people, selling into the Industrial Safety and Controls markets, had little or no knowledge of how their products’ failure rate data compared to their competitors and/or another industry benchmark (such as DOW…

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How Cybersecurity is like a Goldfish

How Cybersecurity is like a Goldfish

Oh look! Squirrel!

I am not much of a blogger. I should be but I’m not. This is strange, because I always have plenty to say.

This subject just gets me going so I am writing about it. I welcome feedback and opinions.

I have been in cybersecurity in…

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Certification and the Environmental Test
  • by John Yozallinas, CFSE
  • Tuesday, August 18, 2015
  • Certification

Certification and the Environmental Test

Functional Safety Assessments (FSA) focus on the relevant functional safety standards that are to be applied to a product in the appropriate industry.  These are standards such as IEC 61511 in the process automation industry, or ISO 26262 in the automotive industry.  And IEC 61508 is like an umbrella…

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The True Meaning Behind Those Fancy Letters on a Signature

The True Meaning Behind Those Fancy Letters on a Signature

Let me ask you a few questions: Does adding letters after a person’s name make them more important? What did that person go through to achieve those letters? If someone has XYZ after their name and another person also has XYZ after their name, are they equal? Did one…

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Back in the Old Days

Back in the Old Days

Some time ago, I was involved with embedded software projects using microprocessors that had limited memory, speed, and I/O resources.  All embedded programming was in assembly code.  All memory variables were global; it was too hard to keep track of stack variables.  The hardware design assumed that any technical…

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  • by Dr. William Goble, CFSE
  • Tuesday, August 04, 2015
  • Certification

Getting Realistic Failure Rate Data - Part 6

Over the course of several blogs , I talked 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…

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Building a Foundation for an IEC 61508 Development Process

Building a Foundation for an IEC 61508 Development Process

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…

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Getting Realistic Failure Rate Data - Part 5

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…

Read More...