Goble, W.

exida LLC, Sellersville, Pennsylvania

HP Automation Safety: The safe failure fraction barrier

Goble, W., exida LLC

Two charts in IEC61508 are getting a lot of attention as engineers begin to implement design processes to meet the standard. These are the "Safe Failure Fraction (SFF)" tables located i..

HP Automation Safety: A lot of work

Goble, W., exida LLC

I was talking to an engineer from a major petrochemical company today about implementing the new safety standards. The discussion covered ISA 84.01 and the new IEC61511. Both are perfor..

HP Automation Safety: Comparing failure rates

Goble, W., exida LLC

Safety integrity level (SIL) verification per ISA84.01 and IEC61508 requires that a probabilistic evaluation be done on the hardware used in a safety instrumented function (SIF). Data n..

HP Automation Safety: SIL verification

Goble, W., exida LLC

Regular readers have a good understanding of the safety life cycle (SLC), one of the fundamental concepts presented in the ANSI/ISA84.01 and IEC61508 functional safety standards. Since ..

HP Automation Safety: Periodic testing – theory versus reality

Goble, W., exida LLC

One of the fundamental concepts in new functional safety design standards is use of the safety life cycle. This is a design process where risks are evaluated, risk reduction targets are..

HP Automation Safety: Safety-certified equipment, so what?

Goble, W., exida LLC

I had a hallway discussion at a recent safety standards committee meeting about how to implement the safety life cycle. One of the fundamental concepts in the safety life cycle is risk-..

HP Automation Safety: Functional safety experts

Goble, W., exida LLC

The job is to cut risk in the HPI. We want to reduce the chances that an incident will hurt someone, pollute the environment or damage equipment and disrupt production. OK, an obvious s..

HP Automation Safety: Separation – control and safety

Goble, W., exida LLC

There are many questions in the minds of engineers working to meet new safety standards like ANSI/ISA S84.01 and IEC 61508. One question that I have heard quite a bit lately relates to ..

HP Automation Safety: Open means flexibility but also risk of reduced safety

Goble, W., exida LLC

I have heard about the promise of "open" control systems for many years now. During the "I'm more open than you are" advertising wars of the early '90s, many benefits were touted. These..

HP Automation Safety: Safety life cycle design saves money

Goble, W., exida LLC

Frequently, it seems like the safety protection part of an automation project is viewed simply as a cost - an unnecessary add-on needed because of some bureaucratic regulation or a fana..