ISO 2394:2015

Overview - ISO 2394:2015 (General principles on reliability for structures)

ISO 2394:2015 establishes a risk- and reliability-informed foundation for decisions on the design, assessment and lifetime management of structures. It sets out general principles, terminology and conceptual approaches that support code makers, structural engineers, asset owners and risk managers when moving from prescriptive rules to reliability-based and risk-informed practice.

Key topics and technical content

ISO 2394 does not prescribe detailed design values; instead it provides a framework covering:

• Fundamentals - aims and functional requirements for structures, target performance levels and the limit state concept.
• Performance modelling - performance indicators, limit states (ultimate, serviceability, condition), time-dependent and system aspects.
• Uncertainty representation - types of uncertainty, probabilistic models, hierarchical modelling, model updating and interpretation of probability.
• Risk-informed decision making - system identification, modelling, risk quantification, decision optimization and acceptance criteria.
• Reliability-based decision making - target failure probabilities, probability of failure calculation, time-variant problems and implementation.
• Semi-probabilistic methods - partial factor method, design-value method and verification approaches for cumulative damage.
• Informative annexes - quality management, lifetime integrity management, design based on observations/experimental models, geotechnical reliability, code calibration, structural robustness and life-safety optimization.

Practical applications - who uses ISO 2394 and why

ISO 2394 is useful to a wide range of stakeholders who need a consistent reliability basis:

• Standards bodies and code committees - for calibrating safety formats and integrating probabilistic principles into national/regional codes.
• Structural and geotechnical engineers - to develop consistent performance models, limit state definitions and to apply reliability calculations or semi-probabilistic methods.
• Asset owners and infrastructure managers - for lifetime management, inspection planning and risk-informed maintenance strategies.
• Researchers and consultants - for developing probabilistic models, experimental-model-based design and robustness assessments.
• Risk managers and decision-makers - to quantify structural risks and optimize risk acceptance and mitigation measures.

Related standards and integration

ISO 2394 is a primer and conceptual foundation that complements national building codes, ISO structural standards and other technical standards addressing material properties, seismic design, geotechnics or inspection. It supports harmonization of structural reliability, risk-informed design, and code calibration across regulatory and professional practice.

Keywords: ISO 2394:2015, structural reliability, risk-informed decision making, limit states, probabilistic models, partial factor method, code calibration, lifetime management.