IEC TR 63039:2016 PDF

Overview

IEC TR 63039:2016 is a Technical Report from the IEC that provides guidance on probabilistic risk analysis for systems composed of electrotechnical items. It focuses on methods to estimate the final event rate at a given initial state and to characterise event properties, types and classifications relevant to risk assessment. The report is applicable (but not limited) to electrotechnical industries where quantitative risk analyses are performed and addresses the effects of uncertainty, events and associated risks.

Key topics

• Terms & concepts: definitions for antecedent/recognised/final states, renewal events and time-to-event measures.
• Event taxonomy: classification of final events as repeatable vs unrepeatable and as producing renewable or unrenewable final states.
• Frequency vs rate: distinction between steady-state final event frequency and final event rate at a specific initial or recognised state.
• Quantitative techniques: guidance on using and adapting graphical and analytical techniques - Event Tree Analysis (ETA), Fault Tree Analysis (FTA) and Markov models - including modified symbols and representation for complex systems.
• State-transition modelling: procedures for modelling time-to-final-event (TTFE), time-to-renewal-event (TTRE) and state transitions.
• Multiple protection layers: analysis of protection architectures (1-out-of-1, 1-out-of-2), common-cause failures and sequence-dependent failures.
• Risk monitoring & estimation: suggested approaches to estimate event frequency/rate from operational monitoring and detection data.
• Illustrative examples: worked examples and annexes (including functional safety applications) to demonstrate methods.

Applications and users

IEC TR 63039 is practical for:

• Reliability, safety and risk engineers performing probabilistic risk assessments of electrotechnical systems.
• Functional safety assessors and system designers who need to translate event models into target failure measures (see relation to IEC 61508).
• Asset managers and maintainers using risk monitoring data to update frequencies/rates and to design protection layers.
• Regulators and certification bodies seeking a consistent, state-based approach to final event estimation.

Typical application areas: power systems, industrial control, transportation electrification, automotive electrical subsystems, and other complex electrotechnical installations where modelling of event occurrence, protection effectiveness and uncertainty is needed.

Related standards

• IEC 61508 (functional safety) - referenced in the report’s annex on functional safety and SIL-related measures.
• Other dependability and safety standards where probabilistic risk analysis and final event metrics are required.

Keywords: probabilistic risk analysis, final event rate, effects of uncertainty, events and associated risks, ETA, FTA, Markov.