Yes, But…Hardware Fault Tolerance

“Therefore, by virtue of the authority vested in me by the Universita Committeeatum E Pluribus Unum, I hereby confer upon you the honorary degree of Th.D.,… er, ‘Doctor of Thinkology’.”  —The Wizard of Oz Most of our readers understand that for a Safety Instrumented Function—a SIF—to have a particular Safety Integrity Level—a SIL—its Average Probability [...]

SIL Certification: Necessary or Sufficient?

“Contrary to what many parents tell their children, talent and hard work are neither necessary nor sufficient for economic success.”  —Robert H. Frank We are all guilty of telling tales we know to be untrue in order to encourage virtuous behavior. Parents tell their children to be good so Santa Clause will come. OSHA tells [...]

By | 2019-05-23T16:10:03+00:00 May 23rd, 2019|Process Safety|0 Comments

Wait For It! Are Trip Delays Okay?

“But the important thing about learning to wait, I feel sure, is to know what you are waiting for.”  —Anna Neagle Many safety instrumented functions (SIFs) are deliberately designed to wait before tripping.  Like a sergeant commanding his troops to “Wait for it!” the SIF designer is anxious that the SIF not trip prematurely. Some [...]