Yes, you can compile part of the technical documentation yourself, provided you have access to the correct underlying information. It is a file that shows how a product has been designed, produced and assessed for safety: a product description, standards used, test results, drawings and the risk analysis. Collecting, organizing and keeping those documents up to date is administrative work that many entrepreneurs can do themselves.
The boundary lies with the content of those documents themselves. Test reports, certificates and technical drawings are usually not drawn up by you, unless you manufacture yourself. That information typically comes from the manufacturer or supplier, and your task is to check whether the file is complete, whether it matches the product and whether it is retained. What role you play in that varies depending on the situation; you will see that in five questions see where you stand.
What belongs in the technical documentation
The regulation does not describe one fixed template, but supervisory authorities usually look at a fixed core: a description of the product and its intended use, the risk analysis, an overview of the standards or guidelines that have been applied, results of tests or inspections where relevant, drawings or specifications where relevant, and the instructions for use with warnings as they also appear on the product page and the label. The exact wording of the regulation can be found on EUR-Lex; that location is free to consult for everyone.
What you can usually do yourself
Organizing existing documents per article, adding a risk analysis based on the characteristics of the product, keeping track of which version is current, and linking the correct warnings to the product page are tasks that fall within the reach of an office manager or compliance officer, without requiring specialized knowledge of materials or test methods. A compliance system helps above all to ensure that nothing is forgotten and everything is findable at the moment when a supervisory authority asks for it.
What usually does not work yourself
Determining whether a product is actually safe, performing physical tests, and issuing a certificate are not tasks that you as a seller or brand owner perform yourself. That assessment belongs to a test laboratory, certification body or the manufacturer who designed the product. Gpsria.eu structures the risk analysis and the file around it, but never gives its own opinion on it and never declares that a product complies with the law; for that assessment we refer you to specialized partners.
Doing it yourself versus having it structured
The difference is therefore not in "do it yourself or outsource" as an absolute choice, but in which part belongs to whom. Collecting and maintaining the file up to date can be done internally; the substantive safety assessment lies with the party that is equipped for it. A system that maintains the file per article, with risk analysis and documentation in one place, saves time especially when you need to quickly demonstrate what has been recorded and when. How such a system works exactly and where the underlying information comes from, you can read on the page that explains it.
When a specialist is needed
If you have products made under your own brand, if the supplier does not provide test documentation, or if you cannot assess whether the supplied documents match the product sold, external advice or a test laboratory is usually the way to go. The same applies to the question of who in practice acts as the responsible person in the EU: that is a role that is not simply "added on."
The topics around risk analysis, supplier documents and retention periods are detailed in the knowledge base, with practical explanations for each situation; you can find that overview in the full topic overview. What the paid part of gpsria.eu contains exactly and what it costs, is clearly stated on the pricing page.
Do you first want to know which role you have in your own chain before you decide what you handle yourself and what you outsource? The free role check gives you an initial indication of that in a couple of minutes, without needing to create an account.