---
title: Design and Manufacturing Information in Technical Documentation
description: Annex II Section 3 requires design and manufacturing information in the technical file. Here is what belongs in it and how to avoid over-documenting or under-documenting.
authors: Tibor Zechmeister, Felix Lenhard
category: Technical Documentation & Labeling
primary_keyword: design manufacturing information technical documentation MDR
canonical_url: https://zechmeister-solutions.com/en/blog/design-manufacturing-information-tech-doc
source: zechmeister-solutions.com
license: All rights reserved. Content may be cited with attribution and a link to the canonical URL.
---

# Design and Manufacturing Information in Technical Documentation

*By Tibor Zechmeister (EU MDR Expert, Notified Body Lead Auditor) and Felix Lenhard.*

> **Section 3 of Annex II of Regulation (EU) 2017/745 requires the technical documentation to contain the design and manufacturing information for the device: enough information to give a general understanding of the design stages, the manufacturing processes, and the identification of all sites — including suppliers and subcontractors — where design and manufacturing activities are performed. The section is neither a dump of every engineering drawing nor a two-paragraph summary. It is the bridge between your internal design controls under EN ISO 13485:2016+A11:2021 clauses 7.3 and 7.5 and the evidence an auditor needs to understand how your device is made and controlled. Most startups either flood this section with raw engineering output or leave it dangerously thin on suppliers. Both failure modes are avoidable.**

**By Tibor Zechmeister and Felix Lenhard. Last updated 10 April 2026.**

---

## TL;DR

- Annex II Section 3 of Regulation (EU) 2017/745 requires design and manufacturing information in the technical documentation, including identification of all sites where design and manufacturing activities are performed.
- Section 3 is the bridge between internal design controls under EN ISO 13485:2016+A11:2021 clause 7.3 (design and development) and production controls under clause 7.5 (production and service provision).
- The legal anchor is MDR Article 10(4), which obliges the manufacturer to draw up and keep up to date the technical documentation as set out in Annex II and Annex III.
- Supplier and subcontractor identification is mandatory. Missing critical suppliers, or listing suppliers in the file who are no longer used, is one of the most common Section 3 findings.
- Section 3 is a summary, not a dump. Raw design outputs live in the design history record under clause 7.3 and are referenced from Section 3, not duplicated into it.

---

## Why Section 3 exists

A Notified Body auditor opening the technical documentation does not need to see every CAD file, every bill of materials revision, or every production router. The auditor needs to understand, at a level sufficient for conformity assessment, how this device was designed and how it is made today. Section 3 of Annex II is the section where that understanding lives.

The phrasing in Regulation (EU) 2017/745 is precise. Annex II Section 3 requires information allowing a general understanding of the design stages applied to the device and of the manufacturing processes — and it requires identification of all sites, including suppliers and subcontractors, where those activities are performed. The word "general" is load-bearing. The auditor is not being asked to reproduce your engineering work. The auditor is being asked to verify that design and manufacturing are controlled, that the controls are traceable, and that the activities are happening at sites the manufacturer knows about and qualifies.

The legal hook sits in MDR Article 10(4). The manufacturer draws up the technical documentation as set out in Annex II and keeps it up to date. Section 3 is part of that obligation. It is not optional, it is not reducible to a placeholder, and it is not satisfied by pointing at the QMS without giving the auditor a way into it from the file itself.

## Section 3 scope — what Annex II actually requires

Section 3 of Annex II covers two things: design and manufacturing information.

On the design side, the section requires information allowing the reader to understand the design stages applied to the device. In practice, this means a description of the design and development process — design planning, inputs, outputs, review, verification, validation, transfer, and change control — together with enough detail about the specific device to show how those stages were applied. It is not the design history record in full. It is a structured summary that references the design history record where an auditor wants to dig deeper.

On the manufacturing side, the section requires information sufficient to understand the manufacturing processes, the production environment, and the controls applied. Again, this is not the batch record archive. It is a description of the processes and process controls at a level that allows the auditor to follow how raw materials become a released device.

And on both sides, Section 3 requires identification of the sites. Every site where design activities happen. Every site where manufacturing activities happen. Every supplier and subcontractor performing activities that the manufacturer has outsourced but remains legally responsible for. The list is not decorative. It is the map the auditor will use to decide whether supplier audits are needed, whether quality agreements exist, and whether the scope of your QMS covers the full chain.

## Design control records — what to include, what to reference

EN ISO 13485:2016+A11:2021 clause 7.3 describes design and development control for medical devices. It covers planning, inputs, outputs, review, verification, validation, transfer to production, and control of design changes. The outputs of clause 7.3 form the design history record — the file your team maintains internally to show that the design process was executed.

Section 3 of Annex II is not the design history record. Section 3 is a written description of the design process as applied to this device, together with references into the design history record where the auditor can inspect the underlying evidence if they choose.

What belongs in Section 3 on the design side:

- A description of the design and development process for the device, structured around the clause 7.3 stages.
- A description of the design inputs as they were translated from the intended purpose and the applicable General Safety and Performance Requirements in Annex I.
- A summary of the design outputs and how they link to the inputs.
- A description of the design review, verification, and validation activities that were performed, with references to the underlying reports in Section 6 of the technical documentation.
- A description of design transfer — how the design moved from development into stable production.
- A description of the design change control process and a summary of significant design changes since the initial release.

What does not belong in Section 3: the raw design outputs themselves. CAD files, source code, detailed schematics, and component-level drawings live in the design history record under clause 7.3. Section 3 references them. Copying them into Section 3 inflates the file without adding clarity and makes every future change a double update.

The discipline is: summary in Section 3, evidence under clause 7.3, cross-references that work both directions.

## Manufacturing processes — the production control story

The manufacturing side of Section 3 maps to clause 7.5 of EN ISO 13485:2016+A11:2021 (production and service provision). Clause 7.5 covers the control of production, the cleanliness of product, installation activities, servicing activities, process validation, identification and traceability, customer property, and preservation of product.

Section 3 describes the manufacturing processes at a level an auditor can follow. The description should cover:

- A process map or narrative of the main manufacturing steps from raw material intake to release of finished device.
- The critical processes and the controls applied to each — in-process checks, inspection points, acceptance criteria.
- Any special processes whose output cannot be fully verified by subsequent inspection or testing, together with a reference to the process validation evidence required by clause 7.5.6. Special processes under clause 7.5.6 typically include sterilisation, cleaning, welding, moulding, and others depending on the device.
- The production environment controls — cleanroom classes if applicable, environmental monitoring, contamination control.
- Identification and traceability, including the batch or serial numbering approach.
- The handling of nonconforming product arising from production.

A Graz company we worked with changed a casing from 3D print to injection moulding — nominally a "minor" manufacturing change. The material contact profile changed, biocompatibility testing had to be re-run, and Section 3 of the technical documentation had to be updated to reflect the new process. The lesson is not that the change was wrong. The change was correct. The lesson is that Section 3 has to track the actual manufacturing reality. If Section 3 still described 3D print while production was on injection moulding, the file would have been out of date the day the first moulded unit shipped.

## Suppliers and subcontractors — the section that gets startups caught

The supplier and subcontractor clause of Annex II Section 3 is the single most common source of Section 3 findings in startup audits. The reason is almost always the same: early teams treat suppliers informally, and Section 3 inherits the informality.

Annex II Section 3 requires identification of all sites where design and manufacturing activities are performed, including suppliers and subcontractors. The list is the starting point. Around the list, the QMS under EN ISO 13485:2016+A11:2021 clause 7.4 (purchasing) has to provide the supporting controls — supplier evaluation and selection, purchasing information, verification of purchased product, and quality agreements for critical suppliers.

What auditors check:

- Is every supplier on the list actually used today? A list with legacy suppliers who are no longer in the chain looks like the file is not maintained.
- Is every critical supplier on the list? Missing a critical supplier — a contract manufacturer, a sterilisation subcontractor, a test laboratory providing part of the release decision — is a major finding.
- Do quality agreements exist for critical suppliers, and do they cover the activities the supplier actually performs?
- Does the supplier list match the purchasing records in the QMS? If the file says one thing and the purchase orders say another, the inconsistency is a finding.
- For suppliers performing parts of the design or manufacturing, is the scope of the outsourced activity described clearly enough that the auditor can understand where the manufacturer's controls end and the supplier's begin?

The fix is not complicated. Build the supplier list in Section 3 from the same source as the purchasing records in the QMS. Keep it current. Flag critical suppliers explicitly. Quality agreements signed, dated, and on file for each critical supplier. This is the clause 7.4 discipline and it is what an experienced auditor will look for within the first twenty minutes of the Section 3 review.

## How Section 3 links to the DHF

Teams with a US regulatory background often ask where the design history file fits. The design history file (DHF) is the terminology used in US FDA quality system requirements (21 CFR Part 820) for the collection of records describing the design history of a finished device. Under MDR and EN ISO 13485:2016+A11:2021, the equivalent record is the output of clause 7.3 — the design and development records for the device.

Section 3 of Annex II is not the DHF. Section 3 is the structured summary of the design and manufacturing story, written for the auditor of the technical documentation. The design history record under clause 7.3 is the underlying evidence. A US-origin company entering the EU market with an existing DHF does not dump the DHF into Section 3. It writes Section 3 as a summary and references the DHF content as the evidence layer underneath. The content may be the same; the structure is not.

The trap for US-origin companies is assuming that because the DHF is "done," Section 3 is done. It is not. Section 3 has to be written as a coherent narrative that follows the Annex II expectations, with supplier identification, site identification, and manufacturing process descriptions that the DHF may not contain in that form.

## Common mistakes in Section 3

- **Dumping raw design outputs into the file.** CAD files, detailed schematics, full BOMs included verbatim. The section becomes unreadable and every revision triggers a cascade of updates.
- **Missing critical suppliers.** The contract manufacturer is listed but the sterilisation subcontractor is not. The test laboratory providing release-decision data is not flagged as critical.
- **Outdated supplier list.** Suppliers who were dropped six months ago are still in the list. New suppliers who came on a month ago are not.
- **No quality agreements for critical suppliers.** The list exists but the agreements behind it do not, or they exist but do not cover the activities the supplier actually performs.
- **Section 3 not tracking the current manufacturing reality.** A process change happened; the section still describes the old process. The file is stale on the day the first unit under the new process ships.
- **Special processes not identified or validated.** Sterilisation, moulding, welding treated as ordinary processes, with no reference to the process validation evidence required by clause 7.5.6.
- **Design transfer not described.** The section describes development but does not explain how the design moved into controlled production.
- **Site list incomplete.** Design is done in one country, manufacturing in another, and the file only mentions one of them.

Each of these is a specific finding waiting to be written. Each is avoidable with discipline that costs nothing except attention.

## The Subtract to Ship angle

Section 3 is a place where teams reliably over-document. The instinct to prove diligence by attaching every engineering artefact to the technical file inflates this section more than any other. The Subtract to Ship move is the opposite: write Section 3 as the auditor-facing summary the Regulation asks for, keep the underlying evidence under clause 7.3 and clause 7.5 in the QMS records, and maintain clean cross-references from Section 3 into those records.

The test is the one we apply everywhere. Every sentence in Section 3 should trace to a specific Annex II requirement or to a supporting clause of EN ISO 13485:2016+A11:2021. Every attached document should be there because Annex II expects it or because it is the minimum needed to support the summary. If it is in the section for any other reason, it comes out. A disciplined Section 3 is typically shorter than a first-draft Section 3 by a significant margin, and easier to keep current. Easier to keep current means the file actually stays current, which is the only state in which it earns its place.

The [Subtract to Ship framework for MDR](/blog/subtract-to-ship-framework-mdr) covers the methodology in full. Applied to Section 3 specifically, it prevents the two failure modes that dominate this section: over-documented design outputs and under-documented supplier chains.

## Reality Check — Where do you stand?

1. Does your Section 3 describe the design stages applied to the device, or does it contain raw design outputs without a narrative?
2. Is every supplier and subcontractor currently performing design or manufacturing activities listed in Section 3, and is every listed entity still in the chain today?
3. Do quality agreements exist for every critical supplier, covering the scope of the activities actually outsourced?
4. Does Section 3 match the current manufacturing reality, including every process change made since the last file revision?
5. Are special processes under EN ISO 13485:2016+A11:2021 clause 7.5.6 identified in Section 3, with references to the process validation evidence?
6. Does Section 3 cross-reference cleanly into the design history record under clause 7.3 and the production records under clause 7.5, instead of duplicating them?
7. If an auditor asked for the site list for design and manufacturing, could you produce it from Section 3 in under two minutes and have it match the purchasing records in your QMS?

## Frequently Asked Questions

**What does MDR Annex II Section 3 require?**
Annex II Section 3 of Regulation (EU) 2017/745 requires the technical documentation to contain information allowing a general understanding of the design stages and the manufacturing processes applied to the device, together with identification of all sites — including suppliers and subcontractors — where design and manufacturing activities are performed.

**Is Section 3 the same as the design history file?**
No. The design history file is a US FDA term (21 CFR Part 820) for the collection of records describing the design history of a finished device. Under MDR and EN ISO 13485:2016+A11:2021 clause 7.3, the equivalent internal record exists, but Section 3 of Annex II is a structured summary written for the technical documentation auditor, not the raw record itself. Section 3 references the underlying design records; it does not reproduce them.

**How detailed does the manufacturing process description need to be?**
Detailed enough to give an auditor a general understanding of the main steps, the critical processes, the process controls, and the production environment. Not detailed enough to replace the underlying batch records or work instructions. The rule of thumb is: the auditor should be able to read Section 3 and understand how the device is made without needing to request additional documents, while still being able to go deeper into the QMS records if they choose.

**Do I have to list every supplier in Section 3?**
You have to list every supplier and subcontractor performing design or manufacturing activities. That includes contract manufacturers, sterilisation subcontractors, test laboratories contributing to release decisions, and design subcontractors. Commodity suppliers of standard off-the-shelf components are treated differently and are covered under the purchasing controls of EN ISO 13485:2016+A11:2021 clause 7.4; the critical suppliers are the ones Section 3 must identify explicitly.

**What happens if a manufacturing process changes after the file is submitted?**
The file has to be updated. MDR Article 10(4) requires the manufacturer to keep the technical documentation up to date. A process change that affects the device as placed on the market has to be reflected in Section 3, and any consequent revalidation — biocompatibility, sterility, performance — has to be in place before units made under the new process ship. Section 3 is not a snapshot; it is a living document.

## Related reading

- [Technical Documentation Under MDR: What It Is and Why Startups Get It Wrong](/blog/technical-documentation-under-mdr) — the pillar post for the technical documentation cluster.
- [MDR Annex II: The Structure of Technical Documentation Explained](/blog/mdr-annex-ii-structure) — the section-by-section walkthrough of Annex II.
- [Device Description in Technical Documentation: What to Include](/blog/device-description-technical-documentation) — Section 1 of Annex II.
- [Labels and Instructions for Use in Technical Documentation](/blog/labels-ifu-technical-documentation) — Section 2 of Annex II.
- [Documenting the GSPR: A Practical Annex I Checklist](/blog/document-gspr-annex-i-checklist) — Section 4 of Annex II.
- [Design Change Control Under MDR](/blog/design-change-control-mdr) — how to keep Section 3 current as the product evolves.
- [Supplier Quality Agreements for MedTech Startups](/blog/supplier-quality-agreements-medtech-startups) — the clause 7.4 counterpart to the Section 3 supplier list.
- [QMS Documentation Under EN ISO 13485 for Startups](/blog/qms-documentation-iso-13485-startups) — the QMS layer that Section 3 depends on.
- [Purchasing Controls and Critical Supplier Management Under MDR](/blog/purchasing-controls-critical-suppliers-mdr) — deeper dive into the supplier control expectations.
- [The Subtract to Ship Framework for MDR Compliance](/blog/subtract-to-ship-framework-mdr) — the methodology this post applies to Section 3.

## Sources

1. Regulation (EU) 2017/745 of the European Parliament and of the Council of 5 April 2017 on medical devices, Article 10(4) (obligation to draw up and keep up to date the technical documentation as set out in Annexes II and III), Annex II Section 3 (design and manufacturing information). Official Journal L 117, 5.5.2017.
2. EN ISO 13485:2016 + A11:2021 — Medical devices — Quality management systems — Requirements for regulatory purposes, clause 7.3 (design and development) and clause 7.5 (production and service provision).

---

*This post is part of the Technical Documentation & Labeling series in the Subtract to Ship: MDR blog. Authored by Felix Lenhard and Tibor Zechmeister. Tibor has reviewed Section 3 content on both sides of the Notified Body table — as the lead auditor opening the section for the first time and as a founder writing it for his own devices. The failure modes described here are the ones that repeat across audit after audit.*

---

*This post is part of the [Technical Documentation & Labeling](https://zechmeister-solutions.com/en/blog/category/technical-documentation) cluster in the [Subtract to Ship: MDR Blog](https://zechmeister-solutions.com/en/blog). For EU MDR certification consulting, see [zechmeister-solutions.com](https://zechmeister-solutions.com).*