Technical documentation for a high-risk AI system under the EU AI Act

AI ACT · TECHNICAL DOCUMENTATION

AI Act Technical Documentation: What a High-Risk AI System Must Contain

A high-risk AI system cannot merely work. It must also be possible to demonstrate how it works: its purpose, data, design, risks, testing, controls, oversight and change history.

That is the objective of the technical documentation required by Article 11 of the AI Act.

The aim is not simply to produce a long document. It is to create a body of evidence that allows a competent authority, notified body or the organisation itself to reconstruct and assess the system clearly and completely.

Annex IV sets the minimum information to be included and requires the system to be understood as more than a model: architecture, data, risks, tests, controls, people, decisions and evidence.

What AI Act technical documentation is

Technical documentation is the structured body of information describing a high-risk AI system and demonstrating how it meets applicable requirements.

It is not one isolated document or a user manual. It may combine specifications, records, reports, diagrams, assessments, test results, data documentation, control evidence, procedures and change records.

What it is for

Demonstrating conformity

It should show how applicable requirements are met.

Supporting assessment

It must give competent authorities, notified bodies, auditors and internal owners clear and complete information.

Maintaining traceability

It should explain how the system evolved and connect requirement → control → test → result → evidence.

When it must be created and updated

Article 11 requires technical documentation before the system is placed on the market or put into service, and requires it to remain up to date.

It should accompany development rather than be reconstructed at the end. Version, model, data, purpose, supplier, architecture and control changes may require an update through AI system change management.

General description of the system

Annex IV begins with a general description, which may include intended purpose, provider, version, previous versions, market route, interfaces, hardware, software and dependencies.

It should answer: which system exactly is being assessed? This matters where multiple models, APIs, suppliers, components and versions are involved.

Intended purpose and scope

Document what the system does, for whom, in what context, for which purpose and within which limits.

Intended purpose shapes risk, AI Act classification, performance, oversight and obligations.

Architecture, software, hardware and integrations

The file may describe architecture, components, software, firmware, hardware, APIs, integrations, interfaces and external systems.

It need not reproduce the code repository, but it should explain operation, external dependencies, third-party services, reused components and foundation models clearly enough for effective assessment.

Development, data and training

Where training is involved, document data origin, preparation, cleaning, labelling, selection, quality, representativeness, training, validation and testing.

Known limitations, bias, assumptions and exclusions may also be needed so that data influence on system behaviour can be understood.

Risks and mitigation measures

Connect the technical file to AI risk management: identified risks, likelihood, impact, treatment, controls, residual risk and acceptance.

Reasonably foreseeable misuse, fundamental rights, security and health may also be relevant. Risks should be visibly translated into measures.

Testing, metrics and validation

Include testing, validation, metrics, acceptance criteria and results. Depending on the system, accuracy, robustness, security, stability, bias, performance and resilience may matter.

The file should state what was tested, how, against which criteria and with what result.

Human oversight

Where applicable, describe human oversight: roles, responsibilities, available information, intervention, override, escalation, stopping and training.

Saying “a person reviews it” is not enough; their authority and practical options should be clear.

Logs, traceability and monitoring

High-risk systems must technically enable automatic event logging. The documentation may describe events, timestamps, decisions, versions, users, errors, interventions and incidents.

Logs support monitoring, audit and investigation. They connect to technical documentation but are not the same thing, and neither replaces instructions for use.

What technical documentation should contain

Annex IV minimum elements can be organised as:

1. General description

Purpose, provider, version, interfaces, hardware and software.

2. Development and architecture

Method, design, components and dependencies.

3. Data

Origin, quality, preparation, validation and representativeness.

4. Risk and mitigation

Identified risks, measures and residual risk.

5. Testing and validation

Metrics, criteria and results.

6. Human oversight

Measures, roles and intervention.

7. Security and robustness

Controls, tests and results.

8. Logging and traceability

Events, records and monitoring.

9. Lifecycle management

Changes, versions, incidents and updates.

10. Conformity evidence

Assessments, declarations, results and supporting evidence.

This structure must reflect the actual system; Annex IV is not an identical closed checklist for every system.

Team reviewing technical documentation for a high-risk AI system

How to organise the technical file

A practical file may combine a structured main document, annexes for architecture, data, tests, risks and controls, stable references to evidence, version control and named owners.

Avoid both one unmaintainable document and hundreds of unstructured files. A certificate or product sheet does not replace the technical file.

What changes during the lifecycle

Documentation does not end at production. Model, data, purpose, supplier, version, integration, control, performance or risk changes may trigger review.

A substantial modification may require renewed classification, risk, conformity and conformity assessment. AI vendor management should also provide evidence of supplier changes.

Common mistakes

Creating documentation at the end

Traceability is lost.

Confusing it with instructions for use

They are related but distinct.

Documenting only the model

The system includes data, architecture, people, controls and integrations.

Weak version control or generic templates

The real system and its history cannot be reconstructed.

Failing to connect risk, controls and evidence

The file becomes fragmented and does not demonstrate effectiveness within the AI governance framework.

Failing to update

An outdated technical file quickly loses value.

Technical documentation makes the system assessable

A high-risk system should not be a documentary black box. It should be explainable, reviewable and auditable, showing the path from design → data → risk → testing → controls → decision.

Technical documentation connects these elements so the organisation can demonstrate that it understands and controls the system.

References

  • Regulation (EU) 2024/1689 — Artificial Intelligence Act.
  • Article 11 — Technical documentation.
  • Annex IV — Technical documentation.
  • Article 12 — Record-keeping.
  • Article 13 — Transparency and provision of information to deployers.
  • Article 15 — Accuracy, robustness and cybersecurity.
  • Article 43 — Conformity assessment.

Could you demonstrate today how your high-risk AI system works?

Technical documentation should connect design, data, risk, testing, controls and evidence in a coherent and up-to-date structure.

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