United States
Change Country Homepage
  • Canada
  • Japan
  • Mexico
  • Netherlands
  • South Africa
  • United Kingdom
  • Member Login
  • |
  • Safety Automation Element List
  • |
  • Contact
  • |
  • COMPANY
    • About Us
    • Locations
    • Key Consultants
    • Clients
    • Career Opportunities
  • SERVICES
    • Certification
    • End User
    • OEM
    • Security
    • Alarm Management
  • SOFTWARE
    • exSILentia
    • PHAx
    • SILAlarm
    • SILStat
    • SERHViewer
    • Software Support
    • All Software
  • TRAINING
    • Course Dates
    • Online Training
    • On-Site Training
    • Virtual Classroom
  • WEBINARS
    • About
    • Scheduled Webinars
    • Recordings
    • Webinar Wednesdays
  • BOOKS
  • RESOURCES
    • Safety Automation Element List
    • Features
    • Brochures / Flyers
    • White Papers
  • WEB STORE
  • BLOG

Blog - exida explains

wgoble's photo
Dr. William Goble, CFSE
Principal Partner

Getting Good Proof Test Coverage Numbers

Tuesday, April 05, 2011

Viewed 9670 times

Several years ago we recognized that proof test coverage was an important variable that must be considered when doing PFDavg calculations. We ran some models and discovered that the difference between “perfect” proof test coverage (100%) and a very good 90% could mean a whole SIL level in the result.  The first question I ask is ‘Why do some engineers still use simplified equations that assume perfect proof test coverage?” Unfortunately the answer I get when I ask them is a question, “What is proof test coverage?” Not a good sign that those doing the work have the competency needed.  But that is another topic for another blog.

Given that proof test coverage is so important, how are good numbers…

Continue Reading >>

Proof Testing • (2) Comments • Permalink

Blog RSS Feed

  • Click to Subscribe

Categories

  • Alarm Management (7)
  • Control System Security (10)
  • Failure Data (15)
  • Functional Safety Certification (37)
  • General (6)
  • Layer of Protection Analysis (LOPA) (2)
  • News (1)
  • Proof Testing (1)
  • Risk Communication (7)
  • Safety Instrumented System (1)
  • Software (9)

Most recent entries

  • The exida SchemeAdded 4 days ago
  • Root Cause AnalysisAdded 6 days ago
  • Certificate Forgery!Added 09 May 2013
  • Which Edition of IEC 61508 is Relevant to Me?Added 07 May 2013
  • How Do You Certify to IEC 61508?Added 30 April 2013
  • Practice Makes Perfect…AlmostAdded 25 April 2013
  • PHA: A must or a MUST?Added 24 April 2013
  • Setting up for FAILUREAdded 18 April 2013
  • The Human Element of Functional Safety (The Challenge)Added 10 April 2013
  • A 100% Pass Rate!Added 03 April 2013
  • Changing the PVST Interval. Hey, my Architectural Constraints changed!Added 21 March 2013
  • Changing the PVST Interval. Hey, my failure rates changed!Added 20 March 2013
  • That is impossible! It has never happened before…Added 13 March 2013
  • Define the Safety Function for a Better CertificationAdded 11 March 2013
  • So What’s an Impact Analysis?Added 06 March 2013

Contact exida

Germany +49-89-49000547
USA +1-215-453-1720
South Africa +27 31 2671564
United Kingdom +44 (0) 2476 214 794
Canada +1-403-475-1943
Mexico +52-55-1-5-18-05-73
Asia +65 6222-5160

Stay Informed

  • Get Updates Via Facebook
  • Follow us on Twitter
  • Youtube Channel
  • RSS Feed of exida News

Resources

Safety Automation Element List
Blog
Features
White Papers
Company Brochures
Web Seminars

Newsletter

Receive our FREE Newsletter that goes out to over 5,000 industry professionals every month

Copyright 2000 - 2013 . exida.com LLC | Site Map