It’s hard to believe that it’s been 10 years since the Deepwater Horizon incident on April 20th 2010. Even today, the Gulf Coast is still feeling the effects. In its latest estimates, BP is looking at a total loss of $65Bn USD, in settlements, fines and compensation. This latest estimate was published in…
exida explains Blog
Entries tagged with: IEC61511
- by Steve Gandy, CFSP
- Thursday, April 30, 2020
- Functional Safety
10 Years After, Has Anything Been Learned from Deepwater Horizon?
- by exida Webinars
- Thursday, January 19, 2023
- Functional Safety
Are You Measuring the Performance of Your SIS?
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…
- by Steve Gandy, CFSP
- Thursday, September 12, 2019
- Industrial Cybersecurity
Are Your Control Systems Really Protected?
I don’t know whether you’ve noticed recently, but the number of cybersecurity alerts issued by CISA (Cybersecurity and Infrastructure Security Agency) seems to be increasing at an alarming rate. The latest alert I’ve seen now relates to GPS tracking systems for children. A device which is supposed to keep…
- by Loren Stewart, CFSE
- Tuesday, December 10, 2019
- Functional Safety
Back to Basics 18 – Route 1H
Route 1H is one of two Architectural constraints options made available in the standards IEC 61508-2 and IEC 61511. Route 1H . Both Route 1H and Route 2H are limitations that impose the hardware selected to implement a safety-instrumented function, regardless of the performance calculated for a subsystem.
Route 1H is…
- by Loren Stewart, CFSE
- Thursday, January 02, 2020
- Functional Safety
Back to Basics 19 – Route 2H
Route 2H is one of two Architectural constraints options made available in the standards IEC 61508-2 and IEC 61511. Route 1H . Both Route 1H and Route 2H are limitations that impose the hardware selected to implement a safety-instrumented function, regardless of the performance calculated for a subsystem.
What exactly is Route 2H…
- by Loren Stewart, CFSE
- Tuesday, January 14, 2020
- Functional Safety
Back to Basics 20 – Safe Failure Fraction, SFF
Safe Failure Fraction (SFF) is defined as the ratio of the average rate of safe failures plus dangerous detected failures of the subsystem to the total average failure rate of the subsystem. It is defined for a single channel (no redundancy, 1oo1).
It is a measurement of the likelihood of…
- by Loren Stewart, CFSE
- Tuesday, January 28, 2020
- Functional Safety
Back to Basics 21 – The B10 Method
The B10 method uses cycle test data to predict failure rates.
A cycle test is done on a set of products (>20) until 10% of the units under test fail. The number of cycles until failure is called the B10 point.
The B10 number of cycles is converted to a…
- by Loren Stewart, CFSE
- Tuesday, February 04, 2020
- Functional Safety
Back to Basics 22 – Cycle Testing
A cycle test is done on a set of products (>20) until 10% of the units under test fail.
The number of cycles is converted to a time period by knowing the cycles per hour in any particular application.
A failure rate is calculated by dividing the 10% failure…
- by Loren Stewart, CFSE
- Tuesday, February 11, 2020
- Functional Safety
Back to Basics 23 – Stiction
What is Stiction?
Stiction is the resistance to the start of motion usually measured as the difference between the external force being applied in order to overcome the static friction and the force to maintain movement between the two contacting or working surfaces.
It can…
- by Steve Gandy, CFSP
- Thursday, February 24, 2022
- Functional Safety
Competency and IEC61511
Many of you who follow exida’s blogs and webinars will know that we often talk about the requirement for competency. In fact, the 2016 edition of IEC61511 specifically addresses competency in more detail now than the 2003 version. The strong emphasis on competency is because the IEC61511 committee recognized that…
- by Steve Gandy, CFSP
- Tuesday, July 14, 2020
- Functional Safety
Functional Safety Management Systems & Engineering Companies
In recent discussions with several engineering and integrators of Safety Instrumented Systems (SIS), it’s become very clear to me that the majority I have spoken to, don’t have any form of Functional Safety Management System (FSMS) in place. This is interesting because one of the changes in the…
- by Steve Gandy, CFSP
- Thursday, September 08, 2016
- Industrial Cybersecurity
How Secure Is Your Safety Instrumented System (SIS)?
As the cybersecurity threats in the industrial world continue to rise, the automation world continues to grapple with how to address these issues. As such, the newly released IEC61511-1: 2016 edition has included a new clause to address this (Clause 8.2.4). In essence, End Users have to carry out…
- by Steve Gandy, CFSP
- Thursday, August 13, 2020
- Functional Safety
IEC61511 and Failure Rates
Most end users I teach in our FSE100 class are not really aware of or fully, understand when we talk about failure rates. For example, what’s a FIT mean? For those end users more versed in this, they understand what is meant by a FIT. Essentially a device can have…
- by Steve Gandy, CFSP
- Wednesday, May 31, 2017
- Functional Safety
Making Use of Leading and Lagging Indicators – Are You Using These for Functional Safety?
Some of you reading this may not be aware or familiar with the terms “leading” and “lagging” indicators, when applied to Functional Safety. The concept isn’t new but does provide significant benefit when applying this to Functional Safety because, if used correctly, these indicators can help significantly improve performance. …
- by Steve Gandy, CFSP
- Tuesday, October 29, 2013
- Certification
Obtaining My CFSE/CFSP Certification: Why Bother?
It’s an interesting question and one I asked myself. For any engineer and/or professional working in the controls business or process industries where safety-related equipment is required, it is essential (per IEC61511-1 Clause 5.2.2: Organization and Resources) to prove competency to carry out any safety-lifecycle activities. So what does…
- by Steve Gandy, CFSP
- Thursday, November 19, 2020
- Functional Safety
The Dos and Don’t of SIS Application Programming
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…
- by Steve Gandy, CFSP
- Tuesday, November 26, 2019
- Functional Safety
The Site Safety Challenge – Do You Follow Good Site Practices?
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…
- by Steve Gandy, CFSP
- Tuesday, June 16, 2020
- Functional Safety
What is Prior Use Justification?
When it comes to IEC61511 and the selection of equipment for use within Safety Instrumented Systems (SIS) and Safety Instrumented Functions (SIF), there are only two methods that can be used to justify selection: IEC61508 Certified devices for the required SIL or Prior Use Justification. Just…
- by Steve Gandy, CFSP
- Thursday, February 06, 2020
- Functional Safety
Why Bother With Systematic Issues?
You may be wondering why this question is being asked? Isn’t it obvious that systematic issues are important and need to be considered? It may be that some of you reading this blog may not even understand what is meant by systematic issues. In which case, it may surprise you to know…