---
title: "ECOs"
description: "Engineering Change Orders — a reviewed, auditable record of every change."
---

import { Image } from 'astro:assets';
import ecoLifecycle from '../../../../assets/diagrams/eco-lifecycle.svg';

An **ECO** (Engineering Change Order) is a proposed change with an approval trail. In simple-plm an ECO is a YAML file that describes *what* is changing, *why*, and *who* signed off — sitting alongside a Git branch that contains the actual part- and BOM-file edits the ECO authorizes.

## States

<Image src={ecoLifecycle} alt="An ECO moves draft → review → approved → released. A reject sends it back to draft." />

- **draft** — the author is still editing. No reviewers notified.
- **review** — reviewers are pinged. They comment and vote.
- **approved** — quorum reached; the ECO is ready to release. The underlying branch is mergeable.
- **released** — merged into `main` and tied to a release tag.

A rejected ECO drops back to **draft** for revision; nothing is ever silently dropped. The full state-transition log lives in the ECO YAML file itself.

## Who can review

Reviewers are configured at the org level. Members with the `reviewer` role can approve; `owner` and `admin` are reviewers implicitly. See [Organizations](/docs/accounts/organizations/) for the role table.

## On disk

```yaml
# plm-data/ecos/ECO-2026-014.yaml
id: ECO-2026-014
title: Switch C12–C18 to AEC-Q200 grade
state: review
author: alice@example.com
created: 2026-04-12
reviewers:
  - bob@example.com
  - carol@example.com
parts_changed:
  - C-100N-0402
description: |
  AEC-Q200 part is in stock and ~3% cheaper. No fit/form impact.
```

The dashboard renders this as a friendly review screen with side-by-side diffs of the affected part and BOM files. See [`plm ecos`](/docs/cli/ecos/) for the CLI.