Overview
IEC TR 63164-2:2020 - "Reliability of industrial automation devices and systems - Part 2: System reliability" - is a Technical Report by the IEC that gives guidance for calculating and presenting the reliability of automation systems. It focuses on deriving system-level reliability (failure rates, reliability values) from the reliability data of individual devices and sub‑systems, where system architectures can be simplified into series, parallel or mixed (series–parallel/redundant) structures. The guidance targets random hardware failures in automation systems and is intended for automation systems themselves (not larger process plants that embed automation).
Key technical topics and requirements
- Calculation methods for system reliability based on component or sub‑system failure rates or reliability values.
- Structure-based approaches: treatment of series, parallel and mixed (redundancy) configurations and reduction techniques to simplify mixed structures.
- Presentation of reliability data: recommended form and reporting conventions so system results are traceable to component data.
- Terminology and metrics: use and definitions of terms such as failure rate (λ), MTTF/MTBF, MTTR, and mission time concepts.
- Practical improvement methods (informative annex): approaches for raising system reliability, including
- fault‑tolerant design,
- error‑avoidance design,
- system derating,
- and measures to reduce or control systematic failures.
- Informative examples (Annex A) that illustrate typical automation system block diagrams and how to apply the calculations.
Practical applications and who uses this standard
Who benefits:
- System integrators and automation designers calculating the reliability of control systems (DCS, PLC, fieldbus-based) from component data.
- Reliability engineers performing quantitative reliability assessments and redundancy analyses.
- Maintenance planners and asset managers using reliability figures for spare‑parts stocking and maintenance scheduling.
- Procurement and QA groups that require standardized presentation of reliability data when specifying or verifying automation systems.
Common applications:
- Estimating system failure probability and expected uptime for production lines.
- Designing redundancy (parallel subsystems) to meet reliability targets.
- Feeding reliability inputs into maintenance planning (MTBF/MTTR assumptions).
- Documenting and communicating system reliability during design reviews and supplier evaluations.
Related standards and references
- IEC TS 63164-1 - Assurance of automation devices reliability data (companion part)
- IEC 60050-192, IEC 61703, IEC 62381 - referenced terminology and mathematical expressions used in reliability engineering
Keywords: IEC TR 63164-2:2020, system reliability, industrial automation, reliability calculation, series-parallel structures, failure rate, MTBF, redundancy, fault-tolerant design, maintenance planning.