Representing confidence in assurance case evidence

Lian Duan, Sanjai Rayadurgam, Mats P E Heimdahl, Oleg Sokolsky, Insup Lee

Research output: Chapter in Book/Report/Conference proceedingConference contribution

8 Scopus citations


When evaluating assurance cases, being able to capture the confidence one has in the individual evidence nodes is crucial, as these values form the foundation for determining the confidence one has in the assurance case as a whole. Human opinions are subjective, oftentimes with uncertainty—it is difficult to capture an opinion with a single probability value. Thus, we believe that a distribution best captures a human opinion such as confidence. Previous work used a doubly-truncated normal distribution or a Dempster-Shafer theory-based belief mass to represent confidence in the evidence nodes, but we argue that a beta distribution is more appropriate. The beta distribution models a variety of shapes and we believe it provides an intuitive way to represent confidence. Furthermore, there exists a duality between the beta distribution and subjective logic, which can be exploited to simplify mathematical calculations. This paper is the first to apply this duality to assurance cases.

Publication series

NameLecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
ISSN (Print)0302-9743
ISSN (Electronic)1611-3349


OtherInternational Conference on Computer Safety, Reliability, and Securitym, SAFECOMP 2015 and held 3rd International Workshop on Assurance Cases for Software-Intensive Systems ASSURE 2015, Workshop on Dependable Embedded and Cyber-Physical Systems and Systems-of-Systems, DECSoS 2015, 2nd International Workshop on the Integration of Safety and Security Engineering, ISSE 2015, Workshop on Reliability and Security Aspects for Critical Infrastructure Protection, ReSA4CI 2015, and 4th InternationalWorkshop on NextGeneration of System Assurance Approaches for Safety-Critical Systems SASSUR, 2015

Bibliographical note

Funding Information:
This work has been partially supported by NSF grants CNS-0931931 and CNS-1035715.

Publisher Copyright:
© Springer International Publishing Switzerland 2015.


  • Beta distribution
  • Opinion triangle
  • Subjective logic


Dive into the research topics of 'Representing confidence in assurance case evidence'. Together they form a unique fingerprint.

Cite this