> For the complete documentation index, see [llms.txt](https://docs.diracinc.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.diracinc.com/videos/tutorials/review-publish-and-share/revisions-and-version-history.md).

# Revisions & Version History

{% embed url="<https://dirac-webflow-videos-cdn.b-cdn.net/gitbook-demo-videos/Revisions%20%26%20Version%20History.mp4>" %}

### What this allows you to do

Iterate on approved work instructions while preserving traceability, auditability, and historical context.

### Types of Revisions

After a work instruction is approved, changes are made through **revisions**. BuildOS supports two revision types, depending on what has changed.

#### Instruction Revisions

Use an **instruction revision** when the CAD model stays the same.

* Creates a new revision starting from the exact state of the previous version
* Allows updates to **sequencing, requirements, animations, and annotations**

#### Model Revisions

Use a **model revision** when the underlying CAD has changed.

* Upload the updated CAD model
* BuildOS automatically maps existing instruction structure to the new model
* Hierarchy and sequencing are carried forward where possible
* New or changed components are clearly identified

Model revisions significantly reduce rework when instructions change due to design updates.

### Why Revisions Matter

Using revisions and version history ensures:

* Changes are fully tracked
* Approved instructions remain auditable
* Teams can safely iterate without losing prior context