BS EN 61078:2016

FOREWORD
INTRODUCTION
1 Scope
2 Normative references
3 Terms and definitions
4 Symbols and abbreviated terms
5 Preliminary considerations, main assumptions, and
   limitations
6 Establishment of system success/failed states
7 Elementary models
8 Qualitative analysis: minimal tie sets and minimal
   cut sets
9 Quantitative analysis: blocks with constant
   probability of failure/success
10 Quantitative analysis: blocks with time dependent
   probabilities of failure/success
11 Boolean techniques for quantitative analysis of
   large models
12 Extension of reliability block diagram techniques
Annex A (informative) - Summary of formulae
Annex B (informative) - Boolean algebra methods
Annex C (informative) - Time dependent probabilities
         and RBD driven Markov processes
Annex D (informative) - Importance factors
Annex E (informative) - RBD driven Petri nets
Annex F (informative) - Numerical examples and curves
Bibliography
Annex ZA (normative) - Normative references to international
         publications with their corresponding
         European publications

Defines the requirements to apply when reliability block diagrams (RBDs) are used in dependability analysis.

IEC 61078:2016 this International Standard describes:
- the requirements to apply when reliability block diagrams (RBDs) are used in dependability analysis;
- the procedures for modelling the dependability of a system with reliability block diagrams;
- how to use RBDs for qualitative and quantitative analysis;
- the procedures for using the RBD model to calculate availability, failure frequency and reliability measures for different types of systems with constant (or time dependent) probabilities of blocks success/failure, and for non-repaired blocks or repaired blocks;
- some theoretical aspects and limitations in performing calculations for availability, failure frequency and reliability measures;
- the relationships with fault tree analysis (see IEC 61025) and Markov techniques (see IEC 61165). This third edition cancels and replaces the second edition published in 2006. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition:
- the structure of the document has been entirely reconsidered, the title modified and the content extended and improved to provide more information about availability, reliability and failure frequency calculations;
- Clause 3 has been extended and clauses have been introduced to describe the electrical analogy, the \'non-coherent\' RBDs and the \'dynamic\' RBDs;
- Annex B about Boolean algebra methods has been extended;
- Annex C (Calculations of time dependent probabilities), Annex D (Importance factors), Annex E (RBD driven Petri net models) and Annex F (Numerical examples and curves) have been introduced. Keywords: reliability block diagram (RBD)