# What is PDM? Product data management explained

What a PDM system does, the problems it solves for engineering teams, how it differs from PLM, and what to look for when you choose one.

## What is product data management (PDM)?

**Product data management (PDM)** is the practice, and the software, for controlling the information that defines a physical product: CAD models, drawings, specifications, bills of materials (BOMs), and the revisions and approvals behind each of them. A PDM system stores that information in one controlled place. It keeps every saved version of a file, marks formally approved states as revisions (A, B, C), and uses check-out and check-in so that two people cannot overwrite each other's work. Changes go through change requests and change orders that record what changed, why and who approved it, and the system logs each action in an audit trail. Roles decide who can view, edit, approve or share data, including external suppliers. As a result, engineering, quality, production and suppliers all build from the same released revision instead of an outdated copy sent by email, and the team can show an auditor how each revision came about.

## What a PDM system does

Most PDM systems share the same core jobs. A tool that lacks one of them works as a file share with extra steps.

- **Version and revision control.** The system keeps every save, and formal revisions (A, B, C) mark what was approved and released.
- **Controlled editing.** Check-in and check-out, or equivalent locking, so two engineers cannot overwrite each other's work.
- **Product structure.** Links between parts, assemblies and documents show where a changed part is used.
- **Change management.** Change requests and change orders (ECR and ECO) capture why something changed, who approved it and what it affects.
- **Release workflows.** Documents move through defined states such as draft, in review and released, with the right approvers at each step.
- **Access control.** Roles decide who can view, edit, approve or share, including external suppliers and partners.
- **Audit trail.** The system logs each action with who, what and when, the evidence auditors ask for.
- **Search and metadata.** You can search part numbers, descriptions, materials and status instead of decoding file names.
- **CAD integration.** Engineers manage files from inside the CAD tools they already use, so the controlled path is also the easy one.

## Versions and revisions are not the same thing

People often use the two words interchangeably. A PDM system treats them differently, and you will feel the difference when something goes wrong.

![Seven saved versions of a file on a line. Version 3 is released as revision A and version 7 as revision B.](https://neopdm.com/diagrams/versions-revisions.en.svg)

| | Version | Revision |
|---|---|---|
| What it is | A saved state of a file | A formally released state of a part or document |
| Created by | Any save or check-in | An approval or change order |
| Typical label | 1, 2, 3 | A, B, C |
| Who relies on it | The engineer working on the design | Production, quality, suppliers and auditors |

Versions record the working history; revisions are what you commit to for everyone downstream.

![Screenshot of an item's lifecycle history in neo. Three versions, each with the time and person for check-out and check-in, and a version note.](https://neopdm.com/screenshots/lifecycle-history.webp "Lifecycle history in neo. 1: every check-out and check-in is recorded with person and time. 2: the version note says what changed.")

## The problems PDM solves

Teams usually buy PDM after one of these happens once too often:

- A part is manufactured from an outdated drawing because the supplier had an old PDF.
- Two engineers edit the same assembly and one set of changes is lost.
- Approvals happen in email threads, and nobody can show later who signed off on what.
- An audit or customer inspection means a week of collecting documents by hand.
- Nobody can say with confidence which revision of a part is in which product.

Each of these is a control problem. Shared drives and general file sync tools store files well, but they have no concept of a revision, of who may release it, or of what else it affects.

## PDM and PLM

People often confuse PDM with **product lifecycle management (PLM)**. PDM controls the engineering data that defines the product, while PLM extends that control across the whole lifecycle: requirements, sourcing, manufacturing, service and end of life. PDM is usually the foundation a PLM strategy is built on, and many hardware teams get most of the value from PDM alone. For a detailed comparison, see [PDM vs PLM](https://neopdm.com/en/pdm-vs-plm).

## Signs your team needs PDM

Better folder discipline will probably not be enough if several of these are true:

- More than a handful of people edit CAD files or engineering documents.
- You ship physical products that are revised after the first release.
- Suppliers or contract manufacturers need drawings and specifications from you.
- You work under a quality system such as ISO 9001 or ISO 13485, or sell into regulated markets.
- Finding "the latest released version" involves asking a colleague.

## PDM and compliance

For regulated hardware, PDM is about evidence. Quality standards and regulations expect you to show that documents are reviewed, approved, controlled and traceable.

- **ISO 9001** (clause 7.5) requires control of documented information: approval before use, review and update, and identification of changes and current revision status.
- **ISO 13485** (clauses 4.2.4 and 4.2.5) applies the same idea to medical devices, with stricter expectations for document and record control.
- **FDA 21 CFR Part 11** sets requirements for electronic records and electronic signatures, including audit trails and signature controls.
- **The EU Cyber Resilience Act (CRA)** requires technical documentation for products with digital elements, including a software bill of materials (SBOM). See our [Cyber Resilience Act guide](https://neopdm.com/en/cyber-resilience-act-guide).

A PDM system does not make you compliant on its own. It produces most of the records an auditor asks for as a side effect of normal work, so you skip the separate project before the audit.

## Cloud PDM or on-premise PDM

Traditional PDM systems such as SOLIDWORKS PDM Professional or Autodesk Vault run on servers you host, while cloud PDM leaves the servers, backups and upgrades to the vendor. Which one fits depends on your data residency rules and how much IT capacity you have. The [cloud PDM guide](https://neopdm.com/en/cloud-pdm) compares the two in detail, including when on-premise is still the better choice.

## How to choose a PDM system

Test these in a trial with your own files:

1. **CAD fit.** Does it work with the CAD tools you use today, from inside those tools?
2. **Revision and release model.** Can you model your real approval flow, including who signs off?
3. **Change management.** Is there a clear path from change request to released revision?
4. **External access.** Can suppliers see exactly what they need, and nothing else?
5. **Audit evidence.** Can you export a complete history for a part in minutes?
6. **Adoption.** Will engineers use it, or will files drift back to shared drives?
7. **Total cost.** Include servers, administration, consultants and upgrades as well as licences.

## Running the test on your own files

The checklist above is easiest to work through in a trial. neo is a cloud PDM for hardware teams and offers a free 3-month pilot on your own data: [take the product tour](https://neopdm.com/en/demo) or [talk to us](https://neopdm.com/en/contact).