IEC 61078-2016 PDF

Full title and description

St IEC 61078-2016 — Reliability block diagrams. International standard that specifies requirements, modelling procedures and calculation methods for the use of reliability block diagrams (RBDs) in dependability analysis, covering qualitative and quantitative techniques, availability and failure‑frequency calculations, and relationships with complementary analysis methods.

Abstract

This standard (IEC 61078:2016, third edition) provides rules and procedures for constructing and using reliability block diagrams for dependability assessments. It describes modelling conventions, calculation methods for reliability, availability and failure frequency for systems with time‑dependent or constant block success/failure probabilities, for repaired and non‑repaired blocks, and it introduces extensions such as non‑coherent and dynamic RBDs. Annexes include Boolean algebra methods, time‑dependent probability calculations, importance factors, RBD→Petri net mappings and numerical examples.

General information

• Status: International Standard — current (third edition, active publication).
• Publication date: 12 August 2016.
• Publisher: International Electrotechnical Commission (IEC).
• ICS / categories: 03.120.01; 03.120.99 (dependability / quality and reliability).
• Edition / version: 3rd edition (2016).
• Number of pages: 250 pages (PDF edition as published by IEC).

Scope

Specifies the requirements to be followed when reliability block diagrams are used in dependability analysis and provides procedures for modelling systems with RBDs. It covers both qualitative and quantitative RBD techniques, methods to calculate availability, failure frequency and reliability measures for different system types (constant or time‑dependent block probabilities; repaired and non‑repaired blocks), and discusses theoretical limitations. The standard also clarifies relationships with complementary analysis methods (notably fault‑tree analysis and Markov techniques) and extends RBD practice to non‑coherent and dynamic cases.

Key topics and requirements

• Definitions, notation and modelling conventions for reliability block diagrams (RBDs).
• Procedures for building RBDs for qualitative dependability analysis.
• Quantitative calculation methods for reliability, availability and failure frequency (constant and time‑dependent probabilities).
• Treatment of repaired and non‑repaired blocks and associated modelling assumptions.
• Description and handling of non‑coherent and dynamic RBDs and their limitations.
• Boolean algebra methods and their application to RBD simplification and computation (extended Annex B/C).
• Importance factors and methods to assess component contributions to system measures (Annex D).
• Mapping of RBD models to Petri‑net representations for advanced dynamic analysis (Annex E).
• Worked numerical examples and curves to illustrate calculation procedures (Annex F).

Typical use and users

Used by reliability and systems engineers, safety analysts, dependability researchers, certification bodies and consultants who model system reliability and availability. Typical applications include system design trade‑offs, maintenance policy evaluation, safety case support, availability targets assessment and education/training in dependability techniques.

Related standards

Directly related to and cross‑referenced with IEC 61025 (Fault tree analysis) and IEC 61165 (Application of Markov techniques) for complementary dependability modelling approaches. National and regional adoptions exist as EN/BS/UNE/LST variants (e.g., EN 61078:2016 and national publications).

Keywords

reliability block diagram; RBD; dependability; availability; failure frequency; dynamic RBD; non‑coherent RBD; Boolean methods; Petri net; importance factors; IEC 61078:2016.

FAQ

Q: What is this standard?

A: IEC 61078:2016 is the third edition international standard that defines how to use reliability block diagrams for dependability analysis, including modelling and calculation methods for reliability and availability.

Q: What does it cover?

A: It covers requirements and procedures for qualitative and quantitative RBD modelling, calculation of availability, failure frequency and reliability for repaired and non‑repaired systems, extensions for non‑coherent and dynamic RBDs, and contains annexes with Boolean methods, time‑dependent calculations, importance factors, Petri‑net mappings and numerical examples.

Q: Who typically uses it?

A: Reliability engineers, safety and systems engineers, dependability researchers, consultants and certification/assessment bodies use the standard to model and quantify system reliability and availability.

Q: Is it current or superseded?

A: The 2016 third edition is the current IEC publication (it cancels and replaces the second edition published in 2006). The IEC webstore lists the 2016 edition as the authoritative, current edition.

Q: Is it part of a series?

A: It is part of the dependability/analysis family of IEC standards issued by IEC TC 56. Complementary standards include IEC 61025 (fault tree analysis) and IEC 61165 (Markov techniques), among other dependability publications.

Q: What are the key keywords?

A: Reliability block diagram, RBD, dependability, availability, failure frequency, dynamic RBD, Boolean methods, Petri net, importance factors, IEC 61078.