Change search
ReferencesLink to record
Permanent link

Direct link
Determination of Beta-factors for Safety Instrumented Systems
Norwegian University of Science and Technology, Faculty of Engineering Science and Technology, Department of Productions and Quality Engineering.
2013 (English)MasteroppgaveStudent thesis
Abstract [en]

Summary Safety instrumented systems are vital safety barriers to reduce the probability of the hazardous events and mitigate the consequences. Safety instrumented systems have been widely used in many kinds of industries. Redundancy is often introduced in safety instrumented systems for higher reliability. Although redundancy has many benefits, the negative effects cannot be ignored. Redundancy induces common cause failures to safety instrumented systems. The common cause failures are a big threat to the reliability of systems, which contributes to many major accidents. Therefore, it is very important to take common cause failures into consideration in risk and reliability assessment for the whole life cycle, especially in the design phase. There are two common cause failure modeling methods: explicit modeling and implicit modeling. The Beta-factor model belongs to implicit modeling and it is the simplest and widely used model. Many common cause failure models have been developed based on the beta-factor model. Three methods for the determination of beta-factor demonstrated in this master thesis: two IEC checklists (IEC 61508-6 and IEC 62061) and unified partial method (UPM). The procedures for beta-factor determination of these three methods are presented, the critical evaluation is performed for the IEC 61508-6 checklist, discussions on the effectiveness of questions are conducted, and a recommended question list of IEC 61508 is provided. Next, a detailed comparison between two checklists (IEC 61508-6 and IEC 62061) is carried out. As well the comparison between the checklist methods and the unified partial method is also demonstrated. Finally, some suggestions for the further work are provided at the end of this master thesis.

Place, publisher, year, edition, pages
Institutt for produksjons- og kvalitetsteknikk , 2013. , 87 p.
URN: urn:nbn:no:ntnu:diva-22227Local ID: ntnudaim:10046OAI: diva2:648682
Available from: 2013-09-16 Created: 2013-09-16 Last updated: 2013-09-16Bibliographically approved

Open Access in DiVA

fulltext(960 kB)3588 downloads
File information
File name FULLTEXT01.pdfFile size 960 kBChecksum SHA-512
Type fulltextMimetype application/pdf
cover(184 kB)21 downloads
File information
File name COVER01.pdfFile size 184 kBChecksum SHA-512
Type coverMimetype application/pdf

By organisation
Department of Productions and Quality Engineering

Search outside of DiVA

GoogleGoogle Scholar
Total: 3588 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Total: 363 hits
ReferencesLink to record
Permanent link

Direct link