Overview
ISO 23132:2020 - "Road vehicles - Extended Vehicle (ExVe) time critical applications" defines a methodology for identifying, classifying and prioritizing time‑constrained and safety‑critical situations that rely on the Extended Vehicle (ExVe) time‑critical interfaces. The standard (RExVeS) helps vehicle manufacturers and system designers determine application priorities to optimize vehicle resource allocation and manage ExVe time‑critical interface resources in connected vehicles.
Key topics and technical requirements
- Classification methodology: A risk‑based approach adapted from ISO 26262‑3 HARA and enriched with systems‑theoretic (STPA) insights to evaluate time‑constrained situations.
- Priority classes: Situations are assigned to one of six priority classes (P1–P6). Safety‑critical situations map to a subset of those classes (P3–P6), based on severity, probability of exposure and controllability.
- Assessment criteria: The methodology uses three main axes to determine priority - severity, probability of exposure, and controllability - rather than prescribing technology‑specific limits.
- Templates and workflow: Normative and informative templates (Annex A and examples) guide the description of scenarios, assignment of priority classes, and documentation of time‑constrained situations.
- Requirements style: Requirements in ISO 23132 are generic and technology‑agnostic, intended as a basis to derive technology‑dependent requirements for implementation of ExVe time‑critical interfaces.
- Design prerequisites: Clause 7 and related guidance outline connected vehicle design prerequisites to ensure ExVe interfaces meet RExVeS requirements.
Practical applications
- Prioritizing peri‑vehicular data communications and low‑latency messaging (e.g., CAM/BSM, DENM) in connected vehicles.
- Guiding OEMs and suppliers on how to allocate limited on‑vehicle resources (processing, network, communication channels) when multiple time‑critical functions compete.
- Supporting the design of ExVe time‑critical interfaces in line with ISO 20077‑1 and ISO 20077‑2 to improve road and vehicle safety.
- Informing safety cases and integration between functional safety (ISO 26262) and SOTIF‑related considerations for connected vehicle features.
Who should use this standard
- Vehicle manufacturers (OEMs) designing ExVe architectures and time‑critical interfaces
- Telematics and connectivity system architects
- Tier‑1 suppliers implementing peri‑vehicular communication functions
- Safety engineers and risk assessors integrating connected‑vehicle scenarios into safety analysis
- Regulators and test organizations evaluating priority management for time‑critical connected functions
Related standards
- ISO 20077‑1 / ISO 20077‑2 (Extended Vehicle methodology and design)
- ISO 26262‑1 (Functional safety vocabulary and concepts)
- ETSI EN 302 637‑2/3, SAE J2735, SAE J2945 (examples of cooperative messaging referenced in the standard)
Keywords: ISO 23132:2020, Extended Vehicle, ExVe, RExVeS, time‑critical, time‑constrained, safety‑critical, vehicle priority management, connected vehicle standards.
Open preview (PDF)Road vehicles — Extended Vehicle (ExVe) time critical applications — General requirements, definitions and classification methodology of time-constrained situations related to Road and ExVe Safety (RExVeS)
