Bypassing in Multi-Instrument Voting Arrangements
I have had yet another discussion today on what it means to put something [...]
Varying Response to Fire Alarms by Industry
During my trip to Houston (from Columbus, OH) last week as we were listening [...]
Sharing BPCS and SIS Field Equipment
… Please don’t. I have recently put together a couple of presentations and a [...]
When Do You Apply Machine Guarding Standards in Process Plant?
I am currently in Perth Australia at the IDC Technologies Safety Control Systems conference. As [...]
Are Permissives Safety Instrumented Functions?
I am often asked the question, “Are permissives safety instrumented functions?” I always respond [...]
Alarm IPL and Alarm Rationalization
Very frequently I run into situations where alarm rationalizations conflict with the results of [...]
Certification of Applications
For a significant amount of time now, end users of safety automation have been [...]
Should SIS Components by SIL Rated?
Certification of SIS components has received a level of respect among some practitioners of [...]
Fire and Gas Maginot Line
I’ve always found it hard to explain why a SIL 3 fire and gas [...]
Fire Detector Cone of Vision
Now that performance-based fire and gas system design is becoming more prevalent, knowledge of [...]
How are Dispersion Models and Fire and Gas Maps Different?
Dispersion modeling and fire and gas mapping are different activities, but are closely related. [...]
What is the Difference Between PHA and LOPA?
I was asked via e-mail what the difference between a PHA and a LOPA [...]
SIS Should Only Be Used as an IPL Once
Another mistake that I commonly run into when reviewing HAZOP/LOPA studies (i.e., studies where [...]
Predicting Reliablility from Components?
So you’re probably wondering why I’ve posted a picture of my son with his [...]
Things LOPA Can’t do… Part 1 of Many
As industry becomes more familiar with LOPA and more studies are performed, I frequently [...]
When LOPA Attacks!
I have to say that I’m a little bit concerned over a large number [...]
SIS Bypass Activity Metrics
Recently a question was posted on the ISA regarding what metrics are available for [...]
Why Calculate Nuisance Trip Rate?
A lot of people have expended a lot of effort in calculating nuisance trip [...]
SIS Documentation
The publication of my Emerson Exchange presentation on the Emerson web site (see below) [...]
PSM Software
There is a lot of process safety management (PSM) software out there, and more [...]
Certification Agencies for Functional Safety
Recently I was asked by a client to comment on the value of a [...]
Utilities in ETT Systems
For energize-to-trip (ETT) systems to operate, power must be available to take the safety [...]
Limit IEC 61511 to SIF
I’m not sure why so many people are so intent to try to pound [...]