exida explains Blog

I was told by an end user engineer that he considers all field devices to be simple Type A devices.  In IEC 61508, Type A is defined as a device with well-defined failure modes, well known failure rates, and behavior under fault conditions that can be completely determined.  Type…

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Each month at exida, we strive to spotlight one of our products that makes the job easier for today's industry professional.  In this blog, I wanted to talk about the PHAx module as part of our exSIlentia Safety Lifecycle Suite.

Process Hazards Analysis (PHA)

Process…

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If you’re like me then you’ve been waiting for the new draft of IEC 61511 to be officially issued since its release has been delayed for some time.  However, a draft has been released and can help in preparing end users for what’s to come.  The question…

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Many products have options and features that are valuable to users.  But not all these features should be permitted while the product is performing a safety function.  For example, HART communications should not be permitted to write data to a transmitter while it’s performing the safety function.  If you…

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The new and updated version of the ISA-18.2 standard (ANSI/ISA-18.2-2016, Management of Alarm Systems for the Process Industries) has now been officially released. This supersedes the original edition (2009). The new version incorporates feedback from 6+ years in the "field" and includes some updates based on the IEC 62682…

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Each month at exida, we strive to spotlight one of our products that makes the job easier for today's industry professional.  In this blog, I wanted to talk about our latest edtion of the SERH (Safety Equipment Realiability Handbook). 

The SERH provides a collection of failure rate data…

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In several of our technical papers over the years, we have noticed that failure rates for the manufacturer, model number are different at different sites, even when the processes were quite similar.  When I have mentioned this to end users and manufacturers, often the response is “Yes, I have…

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How does a team get to play in the NCAA tournament?  They don’t just buy plane tickets and arrive at the arena ready to play whoever else shows up.  In fact, there is a rather rigorous process to determine who gets to play and what seed they are, which…

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The ISA-18.2 and IEC 62682 alarm management standards provide recommended targets for average alarm rate and for alarm floods - a condition during which the alarm rate is greater than the operator can effectively manage (e.g., more than 10 alarm per 10 mins)…

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An interesting question arose recently when creating an FSM plan:

Does the ISA-18.2 standard on alarm management address the claiming of the operator’s response to alarms as a layer of protection?

Not specifically, however the ISA-18.2 standard does require that alarms are rationalized, and that alarm system performance…

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Performing site audits for numerous customers can be very telling.  All sites have their own unique layout, procedures, documentation, and people.  Did you know that failure rates differ from site to site?  Are you surprised?  According to our recent webinar results, the majority of people aren’t, and in fact…

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Good things happened in the fields of functional safety and control system cybersecurity in 2015.  I am not going to include the exciting new Star Wars movie as an event in the list as it does not really fit into the topic. But keeping focused, my highlights is 2015…

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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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Site audits have shown many differences in how things are done from site to site. This impacts many variables in a safety instrumented system!

A key metric for process industry designs is called average Probability of Failure on Demand (PFDavg).  After several studies of many field failure and proof…

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The adoption of the functional safety standards continues to gain momentum in turbine applications. Both industrial and power turbine sites are now requiring compliance to IEC 61511. This blog will review both technical requirements and market trends related to functional safety system design. Market trends will cover which standards…

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