# ISO 9001 Structure and Core Concepts

## The 10-clause structure (Harmonized Structure, formerly Annex SL)

| Clause | Theme | PDCA |
|--------|-------|------|
| 1-3 | Scope, normative references, terms (not audited) | - |
| 4 | Context of the organization | Plan |
| 5 | Leadership | Plan (and the centre of the cycle) |
| 6 | Planning | Plan |
| 7 | Support | Do |
| 8 | Operation | Do |
| 9 | Performance evaluation | Check |
| 10 | Improvement | Act |

ISO 14001, ISO 45001, ISO 27001 and others share this structure, so clauses 4-7 and 9-10 integrate easily.

## Seven quality management principles (ISO 9000:2015)

Customer focus; leadership; engagement of people; process approach; improvement; evidence-based decision making;
relationship management. They explain *why* clauses exist and help when a requirement seems abstract.

## Key concepts

| Concept | Meaning | Where |
|---------|---------|-------|
| Process approach | Manage activities as interrelated processes with inputs, outputs, owners and measures | 0.3, 4.4 |
| Risk-based thinking | Consider what could go wrong or right and act proportionately; replaces preventive action | 0.3.3, 6.1 |
| Documented information | Covers documents and records. "Maintain" = document, "retain" = record | 3.8.6, 7.5 |
| Interested party | Person or organization that can affect or be affected by the QMS | 4.2 |
| Outsourcing | An external provider performs part of a function; control stays with you | 8.4 |
| Nonconformity | Non-fulfilment of a requirement (standard, customer, legal, own system) | 3.6.9, 10.2 |
| Correction vs corrective action | Fixing the instance vs eliminating the cause | 3.12.3, 3.12.2 |
| Verification vs validation | Requirements met vs fit for intended use | 3.8.12, 3.8.13 |

## Verbal forms

**shall** = requirement; **should** = recommendation (notes); **may** = permission; **can** = possibility.
Notes in the standard are guidance, not requirements, but auditors use them to interpret intent.

## Related documents

| Document | Role |
|----------|------|
| ISO 9000 | Fundamentals and vocabulary (definitions used by 9001) |
| ISO 9001 | Requirements (certifiable) |
| ISO 9004 | Guidance for sustained success (not certifiable) |
| ISO 19011 | Guidelines for auditing management systems |
| ISO 9001 Amd 1:2024 | Adds climate change to 4.1 and a note to 4.2 |
| Sector standards | IATF 16949 (automotive), AS9100 (aerospace), ISO 13485 (medical devices) build on or parallel ISO 9001 |

A revision of ISO 9001 is in progress (draft stage in 2025, publication targeted for 2026) and keeps the same
clause structure. Check the edition your certification body audits against and its transition deadline before
quoting clause text.

## Explaining a clause well

1. **Intent first** in one sentence ("what problem this clause prevents").
2. **What it requires**, in the reader's words, split into checkable items.
3. **What it looks like** in their type of company (machine shop, software, hospital lab).
4. **Evidence** an auditor would ask for.
5. **Common mistakes** and how to avoid them.
6. **Links** to related clauses so the reader sees the system, not a checklist.