The Greek symbol λDU is the undetectable dangerous failure rate in functional safety expressed in the unit of measurement of FITs which can be determined through FMEDAs. (FITs (λ) are failures per billion hours, expressed by 10-9 hours).
λDU is the number of dangerous undetected failures…
The travel and group meeting restrictions from COVID-19 have allowed me to catch up on some reading about viruses; not the type that get transmitted to humans. This article is about the Stuxnet virus and what I learned from the book “Countdown to Zero Day: Stuxnet and the Launch of…
At exida, we just finished a Failure Modes and Effects Analysis (FMEA) on a medical ventilator. This was done for a new manufacturer who needed independent design verification. It was a fascinating job. We found lots of pneumatic devices very similar if not identical to the kind used in…
One of the commonly targeted pathways into an Industrial Automation and Control System (IACS) is through compromised remote access such as Virtual Private Networks (VPNs) and Remote Desktop Protocol (RDP). During the Stay at Home Orders and other self-quarantining measures around the globe to combat the COVID-19 pandemic, many…
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…
Get your priorities (distribution) straight
A very common question is posed during alarm management training. Does the recommended alarm priority distribution of ~5% / ~15% / ~80% for high / medium / low priority alarms apply to the rationalized alarm priority distribution (as configured in the control system) or to the annunciatedalarm priority distribution…
The Greek symbol λD represents dangerous failure rates in functional safety, usually expressed in the unit of measurement of FITs, and can be determined through FMEDAs. (FITs (λ) are failures per billion hours, expressed by 10-9 hours).
λD is the number of dangerous failures per…
Hey everybody. I hope this blog finds you, your family, and your colleagues well. At exida, we appreciate the trust you place in our solutions and services to support you in achieving your functional safety, cybersecurity, and alarm management needs. We are committed…
As discussed in Part I, bow tie diagrams provide an easy-to-understand visual representation of risk management information (hazards, potential consequences, barriers, degradation factors and controls). In this article we examine the applicability of bow ties to alarm management.
According to the CCPS book “Bow Ties in Risk Management”,…
The Greek symbol lambda, λ, represents failure rates in functional safety, usually expressed in the unit of measurement of FITS.
λ can be expressed as a total failure rate for a device (λT), or it can be broken down into more specific groupings:
exida, the global leader in functional safety, industrial automation cybersecurity, and alarm management is thrilled to announce a new online testing platform for their CFSE (Certified Functional Safety Expert) and CACE (IEC 62443 Certified Automation Cybersecurity Expert) Certification programs. This also includes the CFSP and CACS…
Creating an alarm philosophy document is often the entry point into the ISA-18.2/IEC 62682 alarm management lifecycle. Many tasked with developing one are discouraged by its length and the barriers it creates. When it comes to using the philosophy document, a common concern is that if the…
Failures In Time or Failure UnIT
FITs is the number of failures per billion hours for a piece of equipment.
It is mentioned in both IEC 61508 and IEC 61511 standards as a preferred unit of measurement expressed by 10-9 hours.
Example: 5 FITs is expressed as 5 failures every 10-9 hours (5x10-9).
When you…
It is tough to receive an email with this message from a prospective CFSE candidate. I know that when I have failed exams, I want to understand what was wrong so I can study those areas of knowledge more deeply and try again. Given the recognition and prestige…
Failure rates are the number of failures per unit time for a piece of equipment which are usually assumed to be a constant value. They can be broken down into several categories, such as safe and dangerous, detected and undetected, and independent/normal and common cause. Failure rates are often…