Pressure can be good. It creates diamonds, right? It can help us focus; may move us to learn something new. It can help reduce procrastination. However pressure can quickly turn into a bad thing if it causes us to skip important process steps or to force a release because…
Since the announcement of the 1st Annual exida Safety Awards program a few weeks ago I have received a few questions and a challenge. The questions from manufacturers mainly focused on how to enter their product and what is the…
The V-model is a lifecycle model useful in the product development process that shows the link between the test specifications at each phase of development. Simply put, it looks like this:
The name comes from the basic shape of the model. …
Part 1 of this blog entry discussed software modeling, modeling notation, and modeling tools. But, what does this have to do with Functional Safety? The IEC 61508 standard has requirements, for certain SIL levels, regarding the use of:
Mechanical CAD and electronic schematic capture tools have been around much longer than graphical software tools. This is primarily because physical objects are more naturally represented as components in a computer-aided design program, and it was more obvious how to design those technologies at the time. The “soft” in…
A question was posed to me this week about why the OREDA failure rate for a solenoid valve was greater than the Failure Modes, Effects, and Diagnostic Analysis (FMEDA) results from exida for a specific manufacturer’s solenoid valve. The person asking the question was clearly challenging the exida…
Todd Stauffer, Director of Alarm Management at exida, takes you through a key part of the Alarm Rationalization process called Alarm Objective Analysis (AOA).
You will learn how to determine what alarms you need (and which one’s you don’t), how to eliminate nuisance alarms, and safely reduce the number…
Look at the picture. What do you see? I see a spring return actuator with
What are the high level potential failures for a ball valve?
Look at the photo. What do you see? I see a ball valve with:
What are the high level potential failures for a ball valve?
ICS cybersecurity standards such as ISA 62443 (formerly ISA 99) and NERC CIP require operators to have policies and procedures in place to monitor and maintain their critical ICS cyber assets. For anything other than very small systems, the obvious choice is to implement systems…
The world of automation has changed significantly over the past 30 years. I have fond memories of starting my career by calibrating, adjusting, and tuning pneumatic control loops while working my way through the electronic age right up to the present digital and cyber generation of automation. If you…
Please see the first entry of the Requirements Management blog series here
Please see the second entry of the Requirements Management blog series here
So, you have a set of detailed safety requirements. You have derived them down to a level of detail you feel spells out…
Please see the first entry of the Requirements Management blog series here.
The concepts of allocation and derivation are sometimes misunderstood when it comes to requirements management. This can lead to confusion and even to safety problems. The process of derivation involves the writing of a new requirement, …
How many development teams have heard those few, innocent words uttered from Marketing/Management toward the end of the development phase of a project, only to have their schedule blown out of the water? The phase of development into which the change is introduced determines the size of the concentric…
There is usually a natural order to things. But there are times when the natural order gets disrupted, and this could be for any number of reasons: we get busy, overloaded with tasks or information, tired, complacent, etc. But when you think about it, most of the excuses we…