ION tracks mBOM changes through explicit versions. See Bills of materials overview for how versioning relates to part revisions and in-flight runs. This page covers what triggers a new version, the version states, and the release flow.
When a new version is needed
| Change | Action |
|---|
| Add a new build requirement | New version |
| Remove a build requirement | New version |
| Change a part on an existing line | New version |
| Change a quantity | New version (significant); in-place edit (clarification) |
| Add or remove a substitute | In-place edit |
| Add or change reference designators | New version |
| Toggle MOA on a line | New version |
| Edit a note or instruction | In-place edit |
Version states
mBOM versions move through:
| State | Meaning |
|---|
| Draft | Editable; not used by any new run |
| In Review | Submitted for review before release |
| Released | Locked structure; new runs against the parent part instantiate from this version |
| Archived | No longer current; preserved for historical reference and in-flight runs that started against it |
Release a new version
- Open the mBOM card on the part page with the version in Draft.
- Make the structural changes.
- Use the status dropdown to move the version through In Review and then Released.
The new version becomes Released, and the previous version moves to Archived. To start the next version once the current one is released, click Create new mBom version in the card header.
In-flight runs
When you release a new mBOM version, in-flight runs are unaffected:
- Each run captures the mBOM version it was started against at create time.
- Mid-flight runs continue running the old version even after the new one is released.
- New runs started after the release pick up the new version.
- The transition is handled per-run. There’s no way to upgrade an existing run to the new mBOM.
To apply a structural change to an in-flight run, use a redline. Switch between versions
The mBOM card on the part page has a version dropdown (for example, v1, v2) in its header. Pick a version to view its lines. Each option shows the version’s status, and Draft versions can be deleted from the dropdown. To see a version’s full line items, open the full mBOM with the Go to full mBom link in the card header.
Programmatic comparison
ION has no built-in page that diffs two mBOM versions. For integrations or scripts, adapt the Compare two aBOM versions query template: fetch the line items for both versions and diff them client-side.
Change-control patterns
Group related changes from an Engineering Change Notice into one release rather than several incremental ones. Write a specific release note, such as “Updated R3 to 10kΩ per ECN-2026-0042”, rather than “minor updates”. Don’t edit archived versions, even for typo fixes, since the historical record is part of the audit trail.