Annex IV

Annex IV of the EU AI Act defines the comprehensive technical documentation that providers of high-risk AI systems must create and maintain. This documentation serves as the evidentiary foundation for conformity assessment, demonstrating to regulators and notified bodies that an AI system meets all applicable requirements. Annex IV is not merely a checklist of documents to produce; it requires evidence that specific processes, controls, and safeguards have actually been implemented in the AI system's development and operation.

The technical documentation must include several major sections. General description: A comprehensive overview of the AI system's intended purpose, how it interacts with hardware and software, versions of relevant software, forms in which the system is placed on the market, and the intended users. Detailed development information: Description of the system architecture, computational resources used, design specifications, development methodologies, and key design choices including rationale for the techniques and solutions adopted. Risk management documentation: Evidence of the risk management system implementation, including risk identification, analysis, evaluation, and mitigation measures throughout the AI system lifecycle. Data governance: Detailed information about training, validation, and testing datasets, including data collection processes, data preparation operations, assumptions about information the data measures, assessment of data availability and suitability, and measures to detect and address biases. Testing and validation: Metrics used to measure accuracy, robustness, and compliance with requirements, test procedures and results, cybersecurity measures, and solutions adopted for compliance. Monitoring and logging: Description of the logging capabilities (Article 12 requirements), monitoring plans for post-market surveillance, and mechanisms for capturing system behavior and human interventions.

The challenge of Annex IV is not just documentation volume but documentation quality. Auditors and notified bodies reviewing Annex IV documentation look for evidence that controls actually exist and function, not just assertions that they do. This means technical documentation must be tied to verifiable artifacts: actual test results, real audit logs, genuine risk assessments that influenced design decisions. Organizations that treat Annex IV as a documentation exercise separate from engineering practice will struggle during conformity assessment, as reviewers probe for the connection between claims and reality.

Start by conducting a gap analysis between your current documentation practices and Annex IV requirements. Most organizations have some technical documentation, but it is rarely structured to satisfy regulatory requirements. Key gaps typically include: insufficient documentation of training data provenance and preprocessing, limited evidence of bias testing and mitigation, missing traceability between risk management decisions and technical implementation, and inadequate logging that does not capture the information auditors need. Building Annex IV documentation retroactively is extremely difficult; the better approach is to integrate evidence capture into your development and deployment workflows from the start.