How to Prepare a Technical File?

Knowing what the technical file is is the starting point; the real challenge is how to prepare it in practice. In this article we go beyond the conceptual definition and walk step by step through how to build a technical file from scratch or from existing documentation, who needs to be involved, and the typical bottlenecks encountered during preparation.

Where Do You Start When Preparing a Technical File?

Preparing a technical file isn't a matter of randomly filling an empty folder with documents — it's a small project that needs to be managed. The first step is to clarify which directive(s) apply to the product and what technical file content those directives require; starting preparation without this can mean having to redo the work from scratch later. The second step is establishing the current state: what drawings, tests and calculations does the company already have, and what's missing? This assessment is known in the industry as a "gap analysis" and forms the backbone of technical file preparation.

Diving straight into collecting documents without a gap analysis is the most common trap inexperienced teams fall into. The usual result is a pile of unnecessarily collected documents while critical gaps (for example, a verification test for a safety function that was never actually performed) go unnoticed until the very last minute. This is why the method we recommend is to first turn the directive's required content headings into a checklist, then map existing documents against that list to make the gaps visible.

Task Allocation: Who Should Do What?

A technical file doesn't get finished on a single person's desk. The R&D/design engineer provides the technical drawings, calculations and design rationale; the quality manager tracks standard compliance and documentation integrity; the production lead verifies consistency between design and manufacturing once mass production starts; and purchasing/the supply chain gathers conformity evidence from sub-component and subsystem suppliers. In small companies these roles can be combined into a single person, but if responsibility is not clearly defined, the file tends to come together piecemeal and inconsistently.

This is where external consultancy comes in: an experienced consultant speeds up the process when it comes to interpreting the legislation, choosing the right standard, and structuring the file to withstand an audit. But because the consultant cannot know the product as well as the company itself, active involvement from the internal team — especially on technical details and design rationale — remains indispensable.

File Structure and Indexing

One of the situations that wastes the most time during an audit is when the file exists "somewhere" but cannot be presented with an organized index. A practical approach is to keep the section headings the directive requires (general description, drawings, risk analysis, list of standards, tests, user manual, declaration of conformity) as a master index file, with a link or reference to the relevant document under each heading. This structure makes things much easier both for internal use and for quick presentation during an audit.

When it comes to product variants, it is usually sufficient to prepare a single main file for models sharing a common design platform, and document the differences between variants (power, size, optional equipment) in a separate appendix section. However, if a variant changes the risk profile (for example, by introducing a different drive system or an accessible moving part), a separate risk assessment needs to be carried out for that variant.

Completing Missing Tests and Calculations

The gap most commonly found during a gap analysis is that tests or calculations required by the claimed harmonized standard were never actually carried out. At this point, whether the company can rely on its own internal testing or needs independent laboratory testing is determined by the product's risk class and the requirements of the relevant standard. Planning this stage early is important, because laboratory tests can take weeks, and leaving them to the last minute directly delays the launch timeline.

Integrating the User Manual and Declaration of Conformity

One of the final stages of the technical file is including the user manual and the EU declaration of conformity in the file. These two documents are usually prepared last, because they need to reflect the final design and the finalized list of applied standards. Putting an early draft of the manual or declaration into the file and forgetting to update it later is a common source of inconsistency in practice — which is why, when closing out the file, it's important to check that these two documents match the current version.

Relevant Directives and Standards

While the preparation methodology is largely independent of the directive, which content headings are mandatory depends on the legislation applied to the product. The Machinery Directive 2006/42/EC (and Machinery Regulation (EU) 2023/1230, which will progressively take its place, applicable from 20 January 2027) defines the technical file content in Annex VII. For electrical/electronic products, the Low Voltage Directive 2014/35/EU, and for products with wireless communication capability, the Radio Equipment Directive 2014/53/EU, bring similar but product-specific additional requirements. Correctly determining which harmonized standard to apply is one of the earliest and most critical decisions in the preparation process.

Step by Step

1. Determine the project scope, the responsible team and the timeline.
2. Take stock of the product and its variants.
3. Scan existing document archives and carry out the gap analysis.
4. Match the applicable directive and harmonized standards.
5. Carry out and report the risk assessment.
6. Plan and complete missing tests, calculations and verification records.
7. Bring technical drawings and diagrams into alignment with the current design.
8. Integrate the user manual and EU declaration of conformity into the file.
9. Bring the file together under a single master index and run an internal verification.
10. Institutionalize version control and the retention plan.

Most Common Mistakes

• Starting preparation under pressure, right before the product launches.
• Leaving the process to a single person without cross-functional involvement.
• Diving straight into collecting documents without doing a gap analysis first.
• Forgetting conformity evidence that needs to be obtained from suppliers.
• Preparing the user manual at the last minute without checking its consistency with the file.
• Repeatedly updating the file without setting up version control.
• Not formally defining who is responsible for the file and where it is stored.
• Leaving laboratory tests to the final stage and blocking the timeline.

Frequently Asked Questions

Conclusion

When treated as a project that proceeds in the right order with the right people involved, technical file preparation produces results that are both faster and more reliable. Starting with a gap analysis, clarifying responsibilities, and gathering the file under a single index ensures both audit-readiness and a sustainable documentation structure across future product revisions. See our article What Is the CE Technical File? for the conceptual framework behind the technical file.