October 8, 2021
Jon Keswick, CFSE

IntroductionSafety Integrity Level (SIL) Verification is needed when a Safety Instrumented Systems (SIS) is one of the critical independent protection layers for process safety. Applications of SIS include automated isolation, trips or interlocks found commonly in oil & gas upstream, refining, chemical and pharmaceutical production.Get the correct inputs firstBefore a Read More

May 6, 2021
Stephen Burke, CFSE

Calculations for verifying a Safety Instrumented Function (SIF) with Safety Integrity Level (SIL) performance requirement are standard in the process industry these days. You will find examples in both the IEC 61508 and IEC 61511 standards and Functional Safety (FS) training courses like those available on this site.There are also Read More

How to select a safety PLC
March 5, 2021
Jon Keswick, CFSE

When it comes to implementing safety instrumented systems (SIS) to comply with functional safety standard IEC 61511, the safety PLC is a pivotal system to specify. So, what are the key questions that you need to ask if choosing a new system supplier? Read more here.What is the difference between standard and Read More

eFunctionalSafety teaches courses about safety instrumented systems
October 7, 2020
Jon Keswick, CFSE

Suppose your staff and contractors need to get up to speed with improving IEC 61511 functional safety competence for safety instrumented systems. If that's the case, this is the right blog for you.Developed over the past seven years, we've delivered many years of experience to hundreds of professionals with our Read More

What is hardware fault tolerance - HFT
September 3, 2020
Jon Keswick, CFSE

You may not know or care much about Hardware Fault Tolerance (HFT) unless you're working in a hazardous industry with Safety Integrity Level *SIL requirements. However, just like the multiple safety systems in your motor vehicle, systems used for protecting hazardous process plants are often built with intentional redundancy, both for Read More

Safety Instrumented Function - SIF Design
July 28, 2020
Jon Keswick, CFSE

A SIF gets specified as an automated independent protection layer (IPL), often as the result of a safety integrity level (SIL) target-setting exercise, also known variously as a SIL determination, SIL study or SIL assessment.Like any many other safety engineering activities, designing a safety instrumented function (SIF) usually involves several Read More

What is MTBF in relation to SIL
July 8, 2020
Jon Keswick, CFSE

Are the terms "Mean Time Between Failures" (MTBF) and "Safety Integrity Level" (SIL) related to each other? Some would think not but read on if you'd like to discover if that's true.MTBFEquipment suppliers have been providing MTBF data for their electrical and electronic equipment for decades. The base information usually Read More

SIF Proof Testing
June 4, 2020
Jon Keswick, CFSE

Ever wondered how to proof test a safety instrumented system? Proof test is a term that was first coined in the original IEC 61511 standard (functional safety - safety instrumented systems for the process industry sector). Unlike regular testing to see if a system performs as required by a specification, a Read More

SIL Verification - PFD or PFH?
February 27, 2020
Jon Keswick, CFSE

This blog will help if you have ever tried to do a SIL verification for probability of failure (PFD or PFH) of a safety function.  A safety integrity level - SIL verification - is needed for compliance with IEC 61511 / ISA 61511 in the process sector and in IEC Read More

online team elearning improves iec 61511 functional safety competence
January 15, 2020
Jon Keswick, CFSE

This article proposes real benefits for team online eLearning for the topic of IEC 61511 functional safety competence with safety instrumented systems.IEC 61511 Functional SafetyMany think of IEC 61511 as a design standard. Yet, it provides much more than that. Strategically adopting IEC 61511 can seriously improve personnel competence and Read More