Abstract
The dynamic flowgraph methodology (DFM) is an approach to
model and analyze the behavior of dynamic systems for
reliability assessment. The methodology can be utilized
to identify how certain postulated top events may occur
in a system. The result is a set of prime implicants
which represent system faults resulting from diverse
combinations of software logic errors, hardware failures,
human errors, and adverse environmental conditions. A
binary decision diagram (BDD) is a data structure used to
represent Boolean functions applied, e.g., in fault tree
analysis and model checking. This paper presents an
alternative DFM approach based on BDD called YADRAT. The
objective of a YADRAT model analysis is to find the root
causes of the query (top event) of interest, similarly to
traditional fault tree analysis. The main difference of
YADRAT compared to the existing DFM approach is that
YADRAT employs a BDD to represent a DFM model. Two
different approaches to solving a BDD model have been
implemented for exact computation of prime implicants.
These approaches have previously been applied in static
failure tree analysis. In this work the ideas for prime
implicant calculation are adapted to a dynamic
reliability approach combined with the multi-valued logic
of DFM. In this paper the basic concepts and algorithms
of YADRAT and the identified strengths and limitations of
the employed approach are discussed. Also a case study
illustrating the usage of YADRAT and a comparison of
computational effort between two BDD implementations is
presented
Original language | English |
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Title of host publication | Proceedings of 2011 International Topical Meeting on Probabilistic Safety Assessment and Analysis, PSA 2011 |
Place of Publication | La Grange Park |
Publisher | American Nuclear Society (ANS) |
Pages | 267-278 |
ISBN (Print) | 978-0-8944-8089-8 |
Publication status | Published - 2011 |
MoE publication type | A4 Article in a conference publication |
Event | International Topical Meeting on Probabilistic Safety Assessment and Analysis, PSA 2011 - Wilmington, NC, United States Duration: 13 Mar 2011 → 17 Mar 2011 |
Conference
Conference | International Topical Meeting on Probabilistic Safety Assessment and Analysis, PSA 2011 |
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Abbreviated title | PSA 2011 |
Country/Territory | United States |
City | Wilmington, NC |
Period | 13/03/11 → 17/03/11 |
Keywords
- reliability analysis
- binary decision diagram
- dynamic flowgraph methodology