Analysis of design parameters in safety-critical computers

Date
2018
Authors
Ahangari, H.
Atik, F.
Ozkok, Y. I.
Yildirim, A.
Ata, S. O.
Ozturk, O.
Advisor
Instructor
Source Title
IEEE Transactions on Emerging Topics in Computing
Print ISSN
2168-6750
Electronic ISSN
Publisher
IEEE Computer Society
Volume
14
Issue
8
Pages
1 - 12
Language
English
Type
Article
Journal Title
Journal ISSN
Volume Title
Abstract

Nowadays, safety-critical computers are extensively used in many civil domains like transportation including railways, avionics, and automotive. In evaluating these safety critical systems, previous studies considered different metrics, but some of safety design parameters like failure diagnostic coverage (C) or common cause failure (CCF) ratio have not been seriously taken into account. Moreover, in some cases safety has not been compared with standard safety integrity levels (IEC-61508: SIL1-SIL4) or even have not met them. Most often, it is not very clear that which part of the system is the Achilles heel and how design can be improved to reach standard safety levels. Motivated by such design ambiguities, we aim to study the effect of various design parameters on safety in some prevalent safety configurations, namely, 1oo2 and 2oo3, where 1oo1 is also used as a reference. By employing Markov modeling, we analyzed the sensitivity of safety to important parameters including: failure rate of processor, failure diagnostic coverage, CCF ratio, test and repair rates. This study aims to provide a deeper understanding on the influence of variation in design parameters over safety. Consequently, to meet appropriate safety integrity level, instead of improving some parts of a system blindly, it will be possible to make an informed decision on more relevant parameters. IEEE

Course
Other identifiers
Book Title
Keywords
Common cause failure, Computers, IEC 61508 standard, IEC Standards, Maintenance engineering, Markov modeling, Markov processes, Reliability, Safety, Safety-critical computer system
Citation
Published Version (Please cite this version)