exida explains Blog

I’ve been teaching our FSE100 course now for nearly 10 years and it always amazes me that when teaching the course, the number of times I find that end users in the class are not really measuring the performance of their SIS.  In most cases, they are doing…

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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.…

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It always amazes me that when teaching our FSE 100 Functional Safety Engineering course, the number of times I find that end users in the class are not really measuring the performance of their SIS. In most cases, they are doing some measurements, but not thoroughly.

It…

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Both Process Safety Analysis (PHA) and Layer of Protection Analysis (LOPA) occur in the early stage of the Functional Safety Lifecycle, detailed in both IEC 61511 and IEC 61508. They both serve significant roles in the whole process safety management. Yet, as a facilitator…

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I am often asked whether extending proof test intervals will be a problem. 

This is a tricky question. The design and engineering SIL calculations for the Safety Instrumented Functions (SIFs) are taking credit for a specific proof test interval with a defined level of coverage, as defined within the…

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The IEC 61511 Standard requires the user to create a Safety Requirements Specification (SRS) for a Safety Instrumented System (SIS) that incorporates all the analysis done during the Risk Assessment, HAZOP/PHA and LOPA reviews.  The SRS falls into two types: an initial conceptual SRS, often referred to as the…

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It’s interesting that the majority of the time when people talk about functional safety, they are usually thinking about hardware: what sensors to use, which logic solver, what actuator, solenoid or valve to select; what voting architecture, etc.  What often gets overlooked, initially, is the application program.

Essentially, when…

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The question of whether companies follow good site safety practices is an interesting one. Firstly, what do we mean by good site safety practices?  I think most companies believe they follow good site safety practices but do they really? Are they really measuring and tracking this?

The basis of having good site…

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Sure, you might think I’ve got it made… sitting here on my perch telling you what you need to do to meet IEC 61508, while you sit there with all the work to do.  Well, it wasn’t always that way.  I was in your shoes, responsible for achieving functional…

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Traceability is about connecting the dots to determine that the web of activities for a functional safety project have followed the proper paths.  Think of it like cheating at hide-n-seek; it provides a shortcut to find all those requirements and design parts that are hidden in your specification documents. …

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