Common cause susceptibility is the enemy of redundancy. Typically when adding redundancy, there is only limited benefit from a PFDavg perspective, simply due to accounting for common cause. Increasing the common cause factor tends to have a negative impact on PFDavg, at least in a standard 1oo2 configuration. In some cases increasing common cause will actually decrease the PFDavg, thereby arguably making a configuration safer by having a higher susceptibility to common cause. This is counter intuitive when only looking within the PFDavg context. This webinar will discuss common cause and review what the impact is on different voting architectures.
exida Recorded Webinars
How Can an Increase in Beta Decrease PFDavg?
Recording Date: April 2016
About the Presenter:
Iwan van Beurden, CFSE
Iwan van Beurden, CFSE is the Chief Technology Officer, Director of Product Development at exida. He supports exida’s end-user services, exida’s manufacturer services, and exida certification activities. He has over 20 years of professional experience in the Functional Safety field. Mr. van Beurden is responsible for the development, maintenance, and certification of the exSILentia® integrated Safety Lifecycle tool and associated products. Mr. van Beurden also performs IEC 61508 development support, Functional Safety Assessments, and a variety of reliability analyses. He supports all safety lifecycle tasks, ranging from the Process Hazard Analysis, Layer of Protection Analysis, SIL Selections, and SIL Verifications, to proof test specification and operational event recording. Mr. van Beurden also performs process gap analyses to determine the level of effort companies need to undertake for compliance with IEC 61508 or IEC 61511. He gives training for exida and is also an ISA fellow and instructor.
Mr. van Beurden previously worked for Yokogawa Industrial Safety Systems in Apeldoorn, the Netherlands. He worked both in the R&D and in the Operations department as a Safety Assessment specialist. He was involved with the implementation of IEC 61508 within Yokogawa Industrial Safety Systems dealing with SIS reliability calculations and the safety education of engineers. Mr. van Beurden is a Certified Functional Safety Expert (CFSE) and a member of ISA. He has published various papers and magazine articles. He holds a Master of Science degree from Eindhoven University of Technology in Eindhoven, the Netherlands, where he majored in reliability engineering and graduated cum laude.